- Changing the guardian-model, policy-recoveryrules, policy-resolutiontrees to a new module: implementation-guardian;

- The new module creates a new kind of implementation (implementation.guardian)

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@819561 13f79535-47bb-0310-9956-ffa450edef68

58 files changed, 4080 insertions, 0 deletions

diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/BlockingInterface.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/BlockingInterface.java
new file mode 100644
index 0000000000..1bb1066435
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/BlockingInterface.java
@@ -0,0 +1,31 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+@Deprecated
+public interface BlockingInterface {
+
+    //@OneWay
+    public void block();
+
+    //@OneWay
+    public void unblock();
+
+    public boolean isBlocked();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroup.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroup.java
new file mode 100644
index 0000000000..2775699843
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroup.java
@@ -0,0 +1,29 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+public interface GuardianGroup extends GuardianPrimitives {
+
+    public static int NORMAL_PARTICIPANT_STATE = 0;
+    public static int SUSPENDED_PARTICIPANT_STATE = 1;
+
+    public void addGuardianMember(GuardianMember guardianMember);
+
+    public boolean removeGuardianMember(GuardianMember guardianMember);
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroupImplementation.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroupImplementation.java
new file mode 100644
index 0000000000..cb7495f9e4
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroupImplementation.java
@@ -0,0 +1,29 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.assembly.Implementation;
+
+public interface GuardianGroupImplementation extends Implementation {
+
+    public void setGuardianProperties(OMElement guardianProperties);
+
+    public OMElement getGuardianProperties();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroupImplementationFactory.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroupImplementationFactory.java
new file mode 100644
index 0000000000..d0758753b3
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianGroupImplementationFactory.java
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+public interface GuardianGroupImplementationFactory {
+
+    public GuardianGroupImplementation createGuardianGroupImplementation();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianMember.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianMember.java
new file mode 100644
index 0000000000..b82bf082b1
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianMember.java
@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public interface GuardianMember extends GuardianPrimitives {
+
+    public void addException(GlobalException ex);
+
+    public Context getCurrentContext();    
+
+    public String getParticipantIdentifier();
+
+    public void setUniqueParticipantID(int id);
+
+    public int getParticipantState();
+
+    public void setParticipantState(int state);
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianPrimitives.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianPrimitives.java
new file mode 100644
index 0000000000..c50e855d30
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/GuardianPrimitives.java
@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import java.util.List;
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalExceptionInterface;
+
+//@Remotable
+public interface GuardianPrimitives {
+
+    //Methods to manage contexts
+    public void enableContext(Context context);
+
+    public void removeContext();
+
+    //Methods to control the signaling of exceptions
+    public void gthrow(GlobalExceptionInterface ex, List<String> participantList);
+
+    public boolean propagate(GlobalExceptionInterface ex);
+
+    //Method to check pending global exceptions
+     public void checkExceptionStatus() throws GlobalException;
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/RecoveryRules.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/RecoveryRules.java
new file mode 100644
index 0000000000..4757615c21
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/RecoveryRules.java
@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import java.util.Map;
+import javax.xml.namespace.QName;
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.assembly.xml.Constants;
+
+public interface RecoveryRules {
+
+    public static final QName RECOVERY_RULES_POLICY_QNAME =
+            new QName(Constants.SCA10_TUSCANY_NS, org.apache.tuscany.sca.implementation.guardian.common.Constants.RECOVERY_RULES);
+
+    public Map<String, OMElement> getRuleElements();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/ResolutionTrees.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/ResolutionTrees.java
new file mode 100644
index 0000000000..d35deff75a
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/ResolutionTrees.java
@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import java.util.Map;
+import javax.xml.namespace.QName;
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.assembly.xml.Constants;
+
+public interface ResolutionTrees {
+
+    public static final QName RESOLUTION_TREES_POLICY_QNAME =
+            new QName(Constants.SCA10_TUSCANY_NS, org.apache.tuscany.sca.implementation.guardian.common.Constants.RESOLUTION_TREES);
+
+    public Map<String, OMElement> getResolutionTreeElements();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/ConcurrentExceptionOcurrenceException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/ConcurrentExceptionOcurrenceException.java
new file mode 100644
index 0000000000..4bfe1320b4
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/ConcurrentExceptionOcurrenceException.java
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class ConcurrentExceptionOcurrenceException extends Exception {
+
+    public ConcurrentExceptionOcurrenceException() {
+        super();
+    }
+
+    public ConcurrentExceptionOcurrenceException(String message) {
+        super(message);
+    }
+
+    public ConcurrentExceptionOcurrenceException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public ConcurrentExceptionOcurrenceException(Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/Constants.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/Constants.java
new file mode 100644
index 0000000000..cf5d56179d
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/Constants.java
@@ -0,0 +1,82 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+import javax.xml.namespace.QName;
+
+public interface Constants {
+
+    String RECOVERY_RULES = "recovery_rules";
+    QName RECOVERY_RULES_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, RECOVERY_RULES);
+
+    String RULE = "rule";
+    QName RULE_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, RULE);
+
+    String NAME = "name";
+    QName NAME_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, NAME);
+
+    String SIGNALED_EXCEPTION = "signaled_exception";
+    QName SIGNALED_EXCEPTION_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, SIGNALED_EXCEPTION);
+
+    String PARTICIPANT = "participant";
+    QName PARTICIPANT_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, PARTICIPANT);
+
+    String MATCH = "match";
+    QName MATCH_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, MATCH);
+
+    String THROW_EXCEPTION = "throw_exception";
+    QName THROW_EXCEPTION_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, THROW_EXCEPTION);
+
+    String CLASS = "class";
+    QName CLASS_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, CLASS);
+
+    String TARGET_CONTEXT = "target_context";
+    QName TARGET_CONTEXT_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, TARGET_CONTEXT);
+
+    String MIN_PARTICIPANT_JOINED = "min_participant_joined";
+    QName MIN_PARTICIPANT_JOINED_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, MIN_PARTICIPANT_JOINED);
+
+    String MAX_PARTICIPANT_JOINED = "max_participant_joined";
+    QName MAX_PARTICIPANT_JOINED_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, MAX_PARTICIPANT_JOINED);
+
+    String AFFECTED_PARTICIPANTS = "affected_participants";
+    QName AFFECTED_PARTICIPANTS_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, AFFECTED_PARTICIPANTS);
+
+    String FIRST = "FIRST";
+    QName FIRST_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, FIRST);
+
+    String LAST = "LAST";
+    QName LAST_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, LAST);
+
+    String ALL = "ALL";
+    QName ALL_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, ALL);
+
+    String RESOLUTION_TREE = "resolution_tree";
+    QName RESOLUTION_TREE_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, RESOLUTION_TREE);
+
+    String RESOLUTION_TREES = "resolution_trees";
+    QName RESOLUTION_TREES_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, RESOLUTION_TREES);
+
+    String EXCEPTION_LEVEL = "exception_level";
+    QName EXCEPTION_LEVEL_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, EXCEPTION_LEVEL);
+
+    String EXCEPTION = "exception";
+    QName EXCEPTION_QNAME = new QName(org.apache.tuscany.sca.assembly.xml.Constants.SCA10_TUSCANY_NS, EXCEPTION);
+    
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/Context.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/Context.java
new file mode 100644
index 0000000000..95c6f3bed6
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/Context.java
@@ -0,0 +1,79 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class Context {
+
+    public static Context CURRENT_CONTEXT = new Context("CURRENT_CONTEXT");
+    public static Context INIT_CONTEXT = new Context("INIT_CONTEXT");
+    public static Context GUARDIAN_CONTEXT = new Context("GUARDIAN_CONTEXT");
+
+    private String name;
+    private List<Class<? extends GlobalException>> exceptionList;
+
+    public Context() {
+        this(null);
+    }
+
+    public Context(String name) {
+        this(name, new LinkedList<Class<? extends GlobalException>>());
+    }
+
+    public Context(String name, List<Class<? extends GlobalException>> exceptionList) {
+        this.name = name;
+        this.exceptionList = exceptionList;
+    }
+
+    public void addException(Class<? extends GlobalException> ex) {
+        this.exceptionList.add(ex);
+    }
+
+    public void setExceptionList(List<Class<? extends GlobalException>> exceptionList) {
+        this.exceptionList = exceptionList;
+    }
+
+    public List<Class<? extends GlobalException>> getExceptionList() {
+        return this.exceptionList;
+    }
+
+    /**
+     * @return the name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * @param name the name to set
+     */
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        return (obj instanceof Context &&
+                (((Context) obj).getName().equals(this.getName()) ||
+                this == Context.CURRENT_CONTEXT ||
+                ((Context) obj) == Context.CURRENT_CONTEXT));
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/GlobalException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/GlobalException.java
new file mode 100644
index 0000000000..022fe1a5f8
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/GlobalException.java
@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class GlobalException extends RuntimeException implements GlobalExceptionInterface {
+
+    private List<String> signalingParticipants;
+    private Context signalingContext;
+    private Context targetContext;
+
+    public GlobalException() {
+        super();
+        signalingParticipants = new LinkedList<String>();
+    }
+
+    public GlobalException(String message) {
+        super(message);
+        signalingParticipants = new LinkedList<String>();
+    }
+
+    public GlobalException(String message, Throwable cause) {
+        super(message, cause);
+        signalingParticipants = new LinkedList<String>();
+    }
+
+    public GlobalException(Throwable cause) {
+        super(cause);
+        signalingParticipants = new LinkedList<String>();
+    }
+
+    /**
+     * @return the signalingContext
+     */
+    public Context getSignalingContext() {
+        return signalingContext;
+    }
+
+    /**
+     * @param signalingContext the signalingContext to set
+     */
+    public void setSignalingContext(Context signalingContext) {
+        this.signalingContext = signalingContext;
+    }
+
+    /**
+     * @return the targetContext
+     */
+    public Context getTargetContext() {
+        return targetContext;
+    }
+
+    /**
+     * @param targetContext the targetContext to set
+     */
+    public void setTargetContext(Context targetContext) {
+        this.targetContext = targetContext;
+    }
+
+    public void putSignalingParticipant(String participant) {
+        signalingParticipants.add(participant);
+    }
+
+    public List<String> getSignalingParticipants() {
+        return signalingParticipants;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/GlobalExceptionInterface.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/GlobalExceptionInterface.java
new file mode 100644
index 0000000000..450d4ae18b
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/GlobalExceptionInterface.java
@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+import java.util.List;
+
+public interface GlobalExceptionInterface {
+
+    /**
+     * @return the signalingContext
+     */
+    public Context getSignalingContext();
+
+    /**
+     * @param signalingContext the signalingContext to set
+     */
+    public void setSignalingContext(Context signalingContext);
+
+    /**
+     * @return the targetContext
+     */
+    public Context getTargetContext();
+
+    /**
+     * @param targetContext the targetContext to set
+     */
+    public void setTargetContext(Context targetContext);
+
+    /**
+     * @return the signalingProcess
+     */
+    public List<String> getSignalingParticipants();
+
+    /**
+     * @param signalingProcess the signalingProcess to set
+     */
+    public void putSignalingParticipant(String participant);
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/InvalidNodeException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/InvalidNodeException.java
new file mode 100644
index 0000000000..ed85661dbf
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/InvalidNodeException.java
@@ -0,0 +1,30 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class InvalidNodeException extends RuntimeException {
+
+    public InvalidNodeException() {
+        super();
+    }
+
+    public InvalidNodeException(String message) {
+        super(message);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/InvalidRegularExpressionException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/InvalidRegularExpressionException.java
new file mode 100644
index 0000000000..99aa027fb8
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/InvalidRegularExpressionException.java
@@ -0,0 +1,30 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class InvalidRegularExpressionException extends RuntimeException {
+
+    public InvalidRegularExpressionException() {
+        super();
+    }
+
+    public InvalidRegularExpressionException(String message) {
+        super(message);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/JoinException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/JoinException.java
new file mode 100644
index 0000000000..890b8704ee
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/JoinException.java
@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class JoinException extends GlobalException {
+
+    public JoinException() {
+        super();
+    }
+
+    public JoinException(String message) {
+        super(message);
+    }
+
+    public JoinException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public JoinException(Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/LeaveException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/LeaveException.java
new file mode 100644
index 0000000000..9684de22ad
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/LeaveException.java
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class LeaveException extends GlobalException {
+
+    public LeaveException() {
+        super();
+    }
+
+    public LeaveException(String message) {
+        super(message);
+    }
+
+    public LeaveException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public LeaveException(Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/ResolutionTreeUtils.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/ResolutionTreeUtils.java
new file mode 100644
index 0000000000..fbf147285e
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/ResolutionTreeUtils.java
@@ -0,0 +1,153 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+import java.util.Collections;
+import java.util.Hashtable;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import org.apache.axiom.om.OMAttribute;
+import org.apache.axiom.om.OMElement;
+
+public class ResolutionTreeUtils {
+
+    //E: Euler tour of the tree obtained by listing the nodes visited in a depth first search of the tree starting from the root. Contains 2n-1 elements
+    private List<String> eulerTour;
+    //L: Array of level numbers such that L[i] contains the tree-depth of the node E[i]. Contains 2n-1 elements
+    private List<Integer> levels;
+    //R: Map of size n such that R<K> contains the index of the first ocurrence of node 'K' in E
+    private Map<String, Integer> rMap;
+    private OMElement root;
+    private int treeSize;
+
+    public ResolutionTreeUtils() {
+        init(null);
+    }
+
+    public ResolutionTreeUtils(OMElement root) {
+        init(root);
+    }
+
+    public void setRoot(OMElement root) {
+        init(root);
+    }
+
+    public List<String> getEulerTourDepthFirstSearch() {
+
+        if (root == null) {
+            throw new NullPointerException("The root musn't be null");
+        }
+
+        if (eulerTour == null) {
+            eulerTour = new LinkedList<String>();
+            levels = new LinkedList<Integer>();
+
+            eulerTourDFSRecursive(root, 0);
+        }
+
+        return eulerTour;
+    }
+
+    public String getLowestCommonAncestor(String node1, String node2) {
+        String lca = null;
+        Integer indexNode1, indexNode2;
+
+        Map<String, Integer> r = getRMap();
+
+        indexNode1 = r.get(node1);
+        indexNode2 = r.get(node2);
+
+        //Check nodes existence
+        if (indexNode1 == null && indexNode2 == null) {
+            throw new InvalidNodeException("Could not find the specified nodes: " + node1 + " and " + node2);
+        } else if (indexNode1 == null) {
+            throw new InvalidNodeException("Could not find the specified nodes: " + node1);
+        } else if (indexNode2 == null) {
+            throw new InvalidNodeException("Could not find the specified nodes: " + node2);
+        }
+
+        int indexLCA;
+        if (indexNode1 < indexNode2) {
+            indexLCA = getRangeMinimumQuery(levels, indexNode1, indexNode2);
+        } else {
+            indexLCA = getRangeMinimumQuery(levels, indexNode2, indexNode1);
+        }
+
+        lca = eulerTour.get(indexLCA);
+
+        return lca;
+    }
+
+    //Get the index of the smallest element between beginIndex and endIndex (both inclusive) in the list
+    private int getRangeMinimumQuery(List list, int beginIndex, int endIndex) {
+
+        List sublist = list.subList(beginIndex, endIndex + 1);
+
+        Object elem = Collections.min(sublist);
+
+        return sublist.indexOf(elem) + beginIndex;
+    }
+
+    private void init(OMElement root) {
+        this.root = root;
+        eulerTour = null;
+        levels = null;
+        rMap = null;
+        treeSize = 0;
+    }
+
+    private void eulerTourDFSRecursive(OMElement node, int level) {
+        String classAttribute = ((OMAttribute) node.getAllAttributes().next()).getAttributeValue();
+        eulerTour.add(classAttribute);
+
+        levels.add(level);
+        treeSize++;
+
+        Iterator children = node.getChildElements();
+
+        OMElement child;
+        while (children.hasNext()) {
+            child = (OMElement) children.next();
+            eulerTourDFSRecursive(child, level + 1);
+            eulerTour.add(classAttribute);
+            levels.add(level);
+        }
+    }
+
+    private Map<String, Integer> getRMap() {
+        if (rMap == null) {
+            rMap = new Hashtable<String, Integer>();
+
+            List<String> tour = getEulerTourDepthFirstSearch();
+            for (int i = 0; i < tour.size(); i++) {
+                String key = tour.get(i);
+                if (!rMap.containsKey(key)) {
+                    rMap.put(key, i);
+                }
+
+                if (rMap.size() == treeSize) {
+                    break;
+                }
+            }
+        }
+        return rMap;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/SuspendException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/SuspendException.java
new file mode 100644
index 0000000000..5ce2f5afd9
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/SuspendException.java
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class SuspendException extends GlobalException {
+
+    public SuspendException() {
+        super();
+    }
+
+    public SuspendException(String message) {
+        super(message);
+    }
+
+    public SuspendException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public SuspendException(Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/UnhandledException.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/UnhandledException.java
new file mode 100644
index 0000000000..a8f9cdfad6
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/common/UnhandledException.java
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.common;
+
+public class UnhandledException extends GlobalException {
+
+    public UnhandledException() {
+        super();
+    }
+
+    public UnhandledException(String message) {
+        super(message);
+    }
+
+    public UnhandledException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public UnhandledException(Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImpl.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImpl.java
new file mode 100644
index 0000000000..5a243560e3
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImpl.java
@@ -0,0 +1,644 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.impl;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import org.apache.axiom.om.OMAttribute;
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.implementation.guardian.common.InvalidRegularExpressionException;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroup;
+import org.apache.tuscany.sca.implementation.guardian.GuardianMember;
+import org.apache.tuscany.sca.implementation.guardian.common.ConcurrentExceptionOcurrenceException;
+import org.apache.tuscany.sca.implementation.guardian.common.Constants;
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalExceptionInterface;
+import org.apache.tuscany.sca.implementation.guardian.common.InvalidNodeException;
+import org.apache.tuscany.sca.implementation.guardian.common.ResolutionTreeUtils;
+import org.apache.tuscany.sca.implementation.guardian.common.SuspendException;
+import org.apache.tuscany.sca.implementation.guardian.xml.RecoveryRulesProcessor;
+import org.apache.tuscany.sca.implementation.guardian.xml.ResolutionTreesProcessor;
+
+public class GuardianGroupImpl implements GuardianGroup {
+
+    private List<GuardianMember> guardianList;
+    private InnerGuardianGroupThread innerThread;
+    private List<GlobalExceptionInterface> concurrentExList;
+    private Map<String, OMElement> resolutionTreeElements;
+    private ResolutionTreeUtils resolutionTreeUtils;
+    private Map<String, OMElement> ruleElements;
+
+    public GuardianGroupImpl(String recoveryRules, String resolutionTrees) {
+        guardianList = new LinkedList<GuardianMember>();
+        concurrentExList = new LinkedList<GlobalExceptionInterface>();
+        innerThread = new InnerGuardianGroupThread();
+        resolutionTreeUtils = new ResolutionTreeUtils();
+
+        setRecoveryRules(recoveryRules);
+        setResolutionTree(resolutionTrees);
+    }
+
+    private void setRecoveryRules(String recoveryRules) {
+        try {
+            FileInputStream fileInputStream = new FileInputStream(recoveryRules);
+            XMLStreamReader xmlReader = XMLInputFactory.newInstance().createXMLStreamReader(fileInputStream);
+
+            RecoveryRulesProcessor processor = new RecoveryRulesProcessor();
+            ruleElements = processor.read(xmlReader).getRuleElements();
+
+        } catch (ContributionReadException ex) {
+            Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+        } catch (XMLStreamException ex) {
+            Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+        } catch (FileNotFoundException ex) {
+            Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+        }
+    }
+
+    private void setResolutionTree(String resolutionTree) {
+
+        try {
+            FileInputStream fileInputStream = new FileInputStream(resolutionTree);
+            XMLStreamReader resolutionTreeReader = XMLInputFactory.newInstance().createXMLStreamReader(fileInputStream);
+
+            ResolutionTreesProcessor processor = new ResolutionTreesProcessor();
+            resolutionTreeElements = processor.read(resolutionTreeReader).getResolutionTreeElements();
+
+        } catch (ContributionReadException ex) {
+            Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+        } catch (XMLStreamException ex) {
+            Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+        } catch (FileNotFoundException ex) {
+            Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+        }
+    }
+
+    public void addGuardianMember(GuardianMember guardianMember) {
+        guardianList.add(guardianMember);
+        guardianMember.setUniqueParticipantID(guardianList.size() - 1);
+    }
+
+    public boolean removeGuardianMember(GuardianMember guardianMember) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public void enableContext(Context context) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public void removeContext() {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public synchronized void gthrow(GlobalExceptionInterface ex, List<String> participantList) {
+
+        concurrentExList.add(ex);
+
+        //Sends a message representing the exception to the other guardian members
+        SuspendException suspendEx = new SuspendException();
+        suspendEx.putSignalingParticipant(ex.getSignalingParticipants().get(0));
+
+        if (participantList == null) {
+            for (GuardianMember g : guardianList) {
+                g.gthrow(suspendEx, null);
+            }
+        } else {
+            for (GuardianMember g : guardianList) {
+                if (participantList.contains(g.getParticipantIdentifier()) ||
+                        g.getParticipantIdentifier().equals(ex.getSignalingParticipants().get(0))) {
+                    g.gthrow(suspendEx, null);
+                }
+            }
+        }
+
+        if (!innerThread.isRunning()) {
+            innerThread.setGlobalException(ex);
+            new Thread(innerThread).start();
+        }
+       
+    }
+
+    public boolean propagate(GlobalExceptionInterface ex) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public void checkExceptionStatus() {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    private class InnerGuardianGroupThread implements Runnable {
+
+        private boolean isRunning;
+        private GlobalExceptionInterface ex = null;
+
+        public InnerGuardianGroupThread() {
+            isRunning = false;
+        }
+
+        public void setGlobalException(GlobalExceptionInterface ex) {
+            this.ex = ex;
+        }
+
+        public GlobalExceptionInterface getGlobalException() {
+            return ex;
+        }
+
+        public void run() {
+            isRunning = true;
+
+            if (ex != null) {
+
+                //Time window of 10 seconds just for tests
+                try {
+                    Thread.sleep(10000);
+                } catch (InterruptedException ex1) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex1);
+                }
+
+                try {
+                    applyRecoveryRules(ex);
+                } catch (ConcurrentExceptionOcurrenceException ce) {
+                    applyConcurrentRecoveryRules();
+                }
+
+                //Clear the concurrent exception list
+                concurrentExList.clear();
+
+                //Set up the participant state to NORMAL
+                for (GuardianMember gm : guardianList) {
+                    if (gm.getParticipantState() == SUSPENDED_PARTICIPANT_STATE) {
+                        gm.setParticipantState(NORMAL_PARTICIPANT_STATE);
+                    }
+                }
+            }
+            isRunning = false;
+        }
+
+        public boolean isRunning() {
+            return isRunning;
+        }
+
+        private void applyRecoveryRules(GlobalExceptionInterface ex) throws ConcurrentExceptionOcurrenceException {
+            ruleTag(ex, ruleElements.values().iterator());
+        }
+
+        private void ruleTag(GlobalExceptionInterface ex, Iterator<OMElement> ruleElements) throws ConcurrentExceptionOcurrenceException {
+            String signaledException;
+            String exceptionName;
+
+            OMElement rule;
+            while (ruleElements.hasNext()) {
+
+                rule = ruleElements.next();
+                signaledException = getAttributeValue(rule, Constants.SIGNALED_EXCEPTION);
+                exceptionName = ex.getClass().getName();
+
+                if (signaledException.equals(exceptionName)) {
+                    participantExceptionTag(ex, rule.getChildElements());
+                    break;
+                }
+            }
+        }
+
+        private void participantExceptionTag(GlobalExceptionInterface ex, Iterator<OMElement> participantElements) throws ConcurrentExceptionOcurrenceException {
+            String matchParticipant;
+            List<GuardianMember> gmList;
+
+            OMElement participant;
+            while (participantElements.hasNext()) {
+                participant = participantElements.next();
+
+                matchParticipant = getAttributeValue(participant, Constants.MATCH);
+                gmList = getMatchingParticipants(matchParticipant, ex);
+
+                if (!gmList.isEmpty()) {
+                    throwExceptionTag(gmList, ex, participant.getChildElements());
+                }
+            }
+        }
+
+        private void throwExceptionTag(List<GuardianMember> gmList, GlobalExceptionInterface ex, Iterator<OMElement> throwExceptionElements) throws ConcurrentExceptionOcurrenceException {
+            String className;
+            String targetContextName;
+            Integer minParticipantJoined;
+            Integer maxParticipantJoined;
+
+            OMElement throwException;
+            while (throwExceptionElements.hasNext()) {
+
+                throwException = throwExceptionElements.next();
+
+                className = getAttributeValue(throwException, Constants.CLASS);
+                targetContextName = getAttributeValue(throwException, Constants.TARGET_CONTEXT);
+
+                try {
+                    minParticipantJoined = Integer.parseInt(getAttributeValue(throwException, Constants.MIN_PARTICIPANT_JOINED));
+                } catch (NumberFormatException nex) {
+                    minParticipantJoined = null;
+                }
+
+                try {
+                    maxParticipantJoined = Integer.parseInt(getAttributeValue(throwException, Constants.MAX_PARTICIPANT_JOINED));
+                } catch (NumberFormatException nexc) {
+                    maxParticipantJoined = null;
+                }
+
+                //Test the min and max joined participants condition
+                if (minParticipantJoined != null && maxParticipantJoined != null) {
+                    if (!(guardianList.size() >= minParticipantJoined && guardianList.size() < maxParticipantJoined)) {
+                        break;
+                    }
+                } else if (minParticipantJoined != null) {
+                    if (!(guardianList.size() >= minParticipantJoined)) {
+                        break;
+                    }
+                } else if (minParticipantJoined != null) {
+                    if (!(guardianList.size() >= minParticipantJoined)) {
+                        break;
+                    }
+                }
+
+                //<affected_participants>
+                String affectedParticipants = affectedParticipantsTag(throwException.getChildElements());
+                int index = -1;
+
+                //Verify if the parameter is an index
+                try {
+                    index = Integer.parseInt(affectedParticipants);
+                } catch (NumberFormatException nexc) {
+                    index = -1;
+                }
+
+                //Create the new exception instance
+                Class exceptionClass;
+                try {
+                    exceptionClass = Class.forName(className);
+
+                    Context targetContext;
+                    if (targetContextName.toUpperCase().equals(Context.CURRENT_CONTEXT.getName().toUpperCase())) {
+                        targetContext = Context.CURRENT_CONTEXT;
+                    } else if (targetContextName.toUpperCase().equals(Context.INIT_CONTEXT.getName().toUpperCase())) {
+                        targetContext = Context.INIT_CONTEXT;
+                    } else {
+                        targetContext = new Context(targetContextName);
+                    }
+                    GlobalException newException = (GlobalException) exceptionClass.newInstance();
+
+                    newException.setTargetContext(targetContext);
+                    newException.setSignalingContext(ex.getSignalingContext());
+                    newException.putSignalingParticipant(ex.getSignalingParticipants().toString());
+
+                    //Check concurrent exception existence
+                    if (concurrentExList.size() > 1) {
+                        throw new ConcurrentExceptionOcurrenceException(concurrentExList.toString());
+                    }
+
+                    //Add the exception to the participants matched
+                    if (index != -1) {
+                        gmList.get(index).addException(newException);
+                    } else if (affectedParticipants != null && affectedParticipants.length() != 0) {
+                        if (affectedParticipants.toUpperCase().equals(Constants.FIRST)) {
+                            gmList.get(0).addException(newException);
+                        } else if (affectedParticipants.toUpperCase().equals(Constants.LAST)) {
+                            gmList.get(gmList.size() - 1).addException(newException);
+                        } else if (affectedParticipants.toUpperCase().equals(Constants.ALL)) {
+                            for (GuardianMember gm : gmList) {
+                                gm.addException(newException);
+                            }
+                        }
+                    } else {
+                        for (GuardianMember gm : gmList) {
+                            gm.addException(newException);
+                        }
+                    }
+
+                } catch (InstantiationException ex1) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex1);
+                } catch (IllegalAccessException ex1) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex1);
+                } catch (ClassNotFoundException ex1) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex1);
+                }
+            }
+        }
+
+        private String affectedParticipantsTag(Iterator<OMElement> affectedParticipantElements) {
+
+            String affectedParticipantValue = null;
+
+            OMElement affectedParticipant;
+            while (affectedParticipantElements.hasNext()) {
+
+                affectedParticipant = affectedParticipantElements.next();
+                affectedParticipantValue = affectedParticipant.getText();
+            }
+
+            if (affectedParticipantValue != null && affectedParticipantValue.length() == 0) {
+                affectedParticipantValue = null;
+            }
+
+            return affectedParticipantValue;
+        }
+
+        private String getAttributeValue(OMElement element, String attributeName) {
+            OMAttribute at;
+            Iterator it = element.getAllAttributes();
+
+            while (it.hasNext()) {
+                at = (OMAttribute) it.next();
+                if (at.getLocalName().equals(attributeName)) {
+                    return at.getAttributeValue();
+                }
+            }
+
+            return null;
+        }
+
+        private void applyConcurrentRecoveryRules() {
+
+            boolean concurrentExOcurrence = false;
+            List<GlobalExceptionInterface> copyConcurrentExList;
+            GlobalExceptionInterface resolvedEx;
+
+            do {
+                System.out.println("Concurrent exceptions: " + concurrentExList);
+
+                copyConcurrentExList = new LinkedList(concurrentExList);
+
+                resolvedEx = checkExceptionResolutionTrees(copyConcurrentExList, resolutionTreeElements.values().iterator());
+
+                concurrentExList.clear();
+
+                System.out.println("Resolved Exception: " + resolvedEx);
+                if (resolvedEx != null) {
+                    System.out.println("List of participants: " + resolvedEx.getSignalingParticipants());
+                }
+
+                try {
+                    //Process the exception list sequentially
+                    if (resolvedEx == null) {
+                        for (GlobalExceptionInterface ex : copyConcurrentExList) {
+                            applyRecoveryRules(ex);
+                        }
+                    } else {
+                        applyRecoveryRules(resolvedEx);
+                    }
+
+                } catch (ConcurrentExceptionOcurrenceException exc) {
+                    concurrentExOcurrence = true;
+                    break;
+                }
+            } while (concurrentExOcurrence);
+        }
+
+        //FIXME: Need to check the exception level
+        private GlobalExceptionInterface checkExceptionResolutionTrees(List<GlobalExceptionInterface> exceptionList, Iterator resolutionTreesElements) {
+
+            OMElement tree;
+            OMElement root;
+            String exceptionLevel = null;
+            GlobalExceptionInterface resolvedEx = null;
+
+            while (resolutionTreesElements.hasNext()) {
+                tree = (OMElement) resolutionTreesElements.next();
+                exceptionLevel = tree.getAttributeValue(Constants.EXCEPTION_LEVEL_QNAME);
+
+                root = (OMElement) tree.getChildElements().next();
+                resolvedEx = checkExceptionResolutionTree(exceptionList, root);
+
+                if (resolvedEx != null) {
+                    break;
+                }
+            }
+
+            return resolvedEx;
+        }
+
+        //Search for the root of the smallest subtree that contains all the concurrently signaled exceptions. If not found, return null.
+        private GlobalExceptionInterface checkExceptionResolutionTree(List<GlobalExceptionInterface> exceptionList, OMElement rootTree) {
+
+            resolutionTreeUtils.setRoot(rootTree);
+            String ex1, ex2;
+            GlobalExceptionInterface resolvedEx = null;
+
+            ex1 = exceptionList.get(0).getClass().getName();
+            for (int i = 1; i < exceptionList.size(); i++) {
+                ex2 = exceptionList.get(i).getClass().getName();
+
+                try {
+                    ex1 = resolutionTreeUtils.getLowestCommonAncestor(ex1, ex2);
+                } catch (InvalidNodeException invalidNodeException) {
+                    ex1 = null;
+                    break;
+                }
+            }
+
+            if (ex1 != null) {
+                Class exceptionClass;
+
+                try {
+                    exceptionClass = Class.forName(ex1);
+                    resolvedEx = (GlobalException) exceptionClass.newInstance();
+
+                    for (GlobalExceptionInterface ex : exceptionList) {
+                        resolvedEx.putSignalingParticipant(ex.getSignalingParticipants().get(0));
+                    }
+
+                } catch (InstantiationException ex) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+                } catch (IllegalAccessException ex) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+                } catch (ClassNotFoundException ex) {
+                    Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex);
+                }
+
+                return resolvedEx;
+
+            } else {
+                return null;
+            }
+        }
+
+        private List<GuardianMember> getMatchingParticipants(String regularExpression, GlobalExceptionInterface signaledException) {
+            List<GuardianMember> matchingParticipants = new LinkedList();
+            String[] splitByComma = regularExpression.split(",");
+
+            //Invalid regular expression
+            if (splitByComma.length > 2) {
+                throw new InvalidRegularExpressionException("The comma ',' operator can only be applied for two expressions");
+            }
+
+            //There is no comma on the regular expression
+            if (splitByComma.length == 1) {
+
+                if (regularExpression.toUpperCase().equals("SIGNALER")) {
+                    for (GuardianMember gm : guardianList) {
+                        if (signaledException.getSignalingParticipants().contains(gm.getParticipantIdentifier())) {
+                            matchingParticipants.add(gm);
+                        }
+                    }
+                } else if (regularExpression.toUpperCase().equals("!SIGNALER")) {
+                    for (GuardianMember gm : guardianList) {
+                        if (!signaledException.getSignalingParticipants().contains(gm.getParticipantIdentifier())) {
+                            matchingParticipants.add(gm);
+                        }
+                    }
+
+                } else {
+                    //Create an java regular expression
+                    String re = createJavaRegularExpression(regularExpression);
+
+                    for (GuardianMember gm : guardianList) {
+                        if (gm.getParticipantIdentifier().matches(re)) {
+                            matchingParticipants.add(gm);
+                        }
+                    }
+                }
+
+            } //There is comma on the regular expression
+            else {
+
+                String element;
+                int index = -1;
+                for (int i = 0; i < splitByComma.length; i++) {
+                    element = splitByComma[i].toUpperCase();
+                    if (element.equals("SIGNALER") || element.equals("!SIGNALER")) {
+                        if (index == -1) {
+                            index = i;
+                        } else {
+                            index = -1;
+                        }
+                    }
+                }
+
+                //Invalid expression
+                if (index == -1) {
+                    throw new InvalidRegularExpressionException("The comma ',' requires a SIGNALER or !SIGNALER element in one side of the expression");
+                }
+
+                String re = createJavaRegularExpression(splitByComma[1 - index]);
+
+                for (GuardianMember gm : guardianList) {
+
+                    //Test if the participant matches with the regular expression
+                    if (gm.getParticipantIdentifier().matches(re)) {
+
+                        //Test if the participant is Signaler
+                        if (splitByComma[index].toUpperCase().equals("SIGNALER")) {
+
+                            if (signaledException.getSignalingParticipants().contains(gm.getParticipantIdentifier())) {
+                                matchingParticipants.add(gm);
+                            }
+                        } //Test if the participant is not Signaler
+                        else {
+                            if (!signaledException.getSignalingParticipants().contains(gm.getParticipantIdentifier())) {
+                                matchingParticipants.add(gm);
+                            }
+                        }
+                    }
+                }
+
+            }
+
+            return matchingParticipants;
+        }
+
+        /* Valid expressions: *, <Context>.*, <Context>, *.<Context>, *.<Context>.*,
+         *                    *.<Context>.*.<Context>.*, <REG_EXP> || <REG_EXP>
+         *
+         * Invalid expressions: *.*, **,
+         *
+         * Not supported yet: !<Context>, !<Context> || <Context>, !(<Context> || <Context>)
+         */
+        private String createJavaRegularExpression(String regularExpression) throws InvalidRegularExpressionException {
+            StringBuffer re = new StringBuffer();
+
+            String[] splitByBar = regularExpression.split("\\|\\|");
+            String[] splitByPeriod;
+
+            for (int i = 0; i < splitByBar.length; i++) {
+
+                splitByPeriod = splitByBar[i].split("\\.");
+
+                if (i > 0) {
+                    re.append("|");
+                }
+
+                re.append("^");
+                for (int j = 0; j < splitByPeriod.length; j++) {
+
+                    //*
+                    if (splitByPeriod[j].equals("*")) {
+
+                        //Validate the regular expression
+                        if (j + 1 != splitByPeriod.length && splitByPeriod[j + 1].equals("*")) {
+                            throw new InvalidRegularExpressionException();
+                        }
+
+                        //*
+                        if (splitByPeriod.length == 1) {
+                            re.append("(\\w+)");
+                        } //*.<CONTEXT>
+
+                        if (j == 0 && splitByPeriod.length != 1) {
+                            re.append("(\\w+\\");
+                            re.append(".)*");
+                        } //<CONTEXT>.*
+                        else {
+                            re.append("(\\");
+                            re.append(".\\w+)*");
+                        }
+                    } //<CONTEXT>
+                    else {
+
+//                    //Validate the regular expression
+//                    if (splitedByPeriod[j].matches("^(\\*)*$")) {
+//                        throw new RuntimeException("Invalid name for a context");
+//                    }
+
+                        //<CONTEXT> || <CONTEXT>.<CONTEXT>.<CONTEXT> || *.<CONTEXT>
+                        if (splitByPeriod.length == 1) {
+                            re.append("(\\w+\\");
+                            re.append(".)*");
+                        }
+
+                        if (j == 0 || j - 1 == 0) {
+                            re.append("(" + splitByPeriod[j] + ")");
+                        } else {
+                            re.append("(\\." + splitByPeriod[j] + ")");
+                        }
+                    }
+                }
+                re.append("$");
+            }
+            return re.toString();
+        }
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImplementationFactoryImpl.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImplementationFactoryImpl.java
new file mode 100644
index 0000000000..cf6b3245ce
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImplementationFactoryImpl.java
@@ -0,0 +1,43 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.impl;
+
+import org.apache.tuscany.sca.assembly.AssemblyFactory;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementation;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementationFactory;
+import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceFactory;
+
+public class GuardianGroupImplementationFactoryImpl implements GuardianGroupImplementationFactory {
+
+    private AssemblyFactory assemblyFactory;
+    private JavaInterfaceFactory javaFactory;
+
+    public GuardianGroupImplementationFactoryImpl(AssemblyFactory assemblyFactory, JavaInterfaceFactory javaFactory) {
+        this.assemblyFactory = assemblyFactory;
+        this.javaFactory = javaFactory;
+    }
+
+    public GuardianGroupImplementation createGuardianGroupImplementation() {
+        return new GuardianGroupImplementationImpl(assemblyFactory, javaFactory);
+    }
+    
+//    public GuardianGroupImplementation createGuardianGroupImplementation() {
+//        return new GuardianGroupImplementationImpl();
+//    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImplementationImpl.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImplementationImpl.java
new file mode 100644
index 0000000000..7520846d55
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianGroupImplementationImpl.java
@@ -0,0 +1,134 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.impl;
+
+import org.apache.tuscany.sca.implementation.guardian.*;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.assembly.AssemblyFactory;
+import org.apache.tuscany.sca.assembly.ConstrainingType;
+import org.apache.tuscany.sca.assembly.Property;
+import org.apache.tuscany.sca.assembly.Reference;
+import org.apache.tuscany.sca.assembly.Service;
+import org.apache.tuscany.sca.interfacedef.InvalidInterfaceException;
+import org.apache.tuscany.sca.interfacedef.java.JavaInterface;
+import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceContract;
+import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceFactory;
+
+public class GuardianGroupImplementationImpl implements GuardianGroupImplementation {
+
+    private AssemblyFactory assemblyFactory;
+    private JavaInterfaceFactory javaFactory;
+    private List<Service> services = new ArrayList<Service>();
+    private OMElement guardianProperties;
+
+    public GuardianGroupImplementationImpl(AssemblyFactory assemblyFactory,
+            JavaInterfaceFactory javaFactory) {
+
+        this.assemblyFactory = assemblyFactory;
+        this.javaFactory = javaFactory;
+        this.guardianProperties = null;
+    }
+    
+    private void introspectServices(AssemblyFactory assemblyFactory, JavaInterfaceFactory javaFactory) {
+
+        Service guardianService = assemblyFactory.createService();
+
+        guardianService.setName("GuardianGroup");
+
+        JavaInterface guardianInterface;
+
+        try {
+            guardianInterface = javaFactory.createJavaInterface(GuardianGroup.class);
+        } catch (InvalidInterfaceException ex) {
+            throw new IllegalArgumentException(ex);
+        }
+
+        JavaInterfaceContract guardianInterfaceContract = javaFactory.createJavaInterfaceContract();
+
+        guardianInterfaceContract.setInterface(guardianInterface);
+
+        guardianService.setInterfaceContract(guardianInterfaceContract);
+
+        services.add(guardianService);
+    }
+
+    public void setGuardianProperties(OMElement guardianProperties) {
+        this.guardianProperties = guardianProperties;
+    }
+
+    public OMElement getGuardianProperties() {
+        return this.guardianProperties;
+    }
+
+    @Override
+    public String getURI() {
+        // The Guardian Model implementation does not have a URI
+        return null;
+    }
+
+    @Override
+    public void setURI(String arg0) {
+        // The Guardian Model implementation does not have a URI
+    }
+
+    @Override
+    public List<Service> getServices() {
+        if (services == null || services.size() == 0) {
+            introspectServices(assemblyFactory, javaFactory);
+        }
+        return services;
+    }
+
+    @Override
+    public List<Reference> getReferences() {
+        // The Guardian Model implementation does not support references
+        return Collections.emptyList();
+    }
+
+    @Override
+    public List<Property> getProperties() {
+        // The sample DATA implementation does not support properties
+        return Collections.emptyList();
+    }
+
+    @Override
+    public ConstrainingType getConstrainingType() {
+        // The Guardian Model implementation does not support constrainingTypes
+        return null;
+    }
+
+    @Override
+    public void setConstrainingType(ConstrainingType arg0) {
+        // The Guardian Model implementation does not support constrainingTypes
+    }
+
+    @Override
+    public boolean isUnresolved() {
+        // The Guardian Model implementation is always resolved
+        return false;
+    }
+
+    @Override
+    public void setUnresolved(boolean arg0) {
+        // The Guardian Model implementation is always resolved
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianMemberImpl.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianMemberImpl.java
new file mode 100644
index 0000000000..80b9321e79
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/GuardianMemberImpl.java
@@ -0,0 +1,177 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.impl;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+import java.util.Stack;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalExceptionInterface;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroup;
+import org.apache.tuscany.sca.implementation.guardian.GuardianMember;
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+import org.apache.tuscany.sca.implementation.guardian.common.JoinException;
+import org.apache.tuscany.sca.implementation.guardian.common.SuspendException;
+import org.osoa.sca.annotations.Destroy;
+import org.osoa.sca.annotations.Init;
+import org.osoa.sca.annotations.Reference;
+import org.osoa.sca.annotations.Scope;
+import org.osoa.sca.annotations.Service;
+
+@Service(GuardianMember.class)
+@Scope("COMPOSITE")
+public class GuardianMemberImpl implements GuardianMember {
+
+    private int participantState;
+    private Stack<Context> contextList;
+    
+    private Queue<GlobalException> exceptionQueue;
+    @Reference(name = "guardian_group", required = true)
+    public GuardianGroup guardianGroup;
+    private int id;
+    //FIXME: Review the usage of this variable
+    private boolean exceptionThrown;
+
+    public GuardianMemberImpl() {
+        contextList = new Stack<Context>();
+        contextList.add(Context.INIT_CONTEXT);
+        exceptionQueue = new LinkedList<GlobalException>();
+        participantState = GuardianGroup.NORMAL_PARTICIPANT_STATE;
+        exceptionThrown = false;
+    }
+
+    @Init
+    public void init() {
+        guardianGroup.addGuardianMember(this);
+    }
+
+    @Destroy
+    public void destroy() {
+        guardianGroup.removeGuardianMember(this);
+    }
+
+    public void addException(GlobalException ex) {
+        exceptionQueue.add(ex);
+    }
+
+    public Context getCurrentContext() {
+        return contextList.peek();
+    }
+ 
+
+    public void enableContext(Context context) {
+        //Update the context list with the related set of exceptions
+        contextList.push(context);
+
+        if (contextList.size() == 2) {
+            JoinException ex = new JoinException();
+            ex.setSignalingContext(context);
+            ex.putSignalingParticipant(getParticipantIdentifier());
+            gthrow(ex, null);
+        }
+
+    }
+
+    public void removeContext() {
+        if (!contextList.isEmpty()) {
+            contextList.pop();
+        }
+    }
+
+    //If participantList is null then signal to ALL participants
+    public void gthrow(GlobalExceptionInterface ex, List<String> participantList) {
+        //1)Block the participant until raise an exception
+
+        if (!(ex instanceof SuspendException)) {
+            //Set the exception's parameters
+            ex.setSignalingContext(getCurrentContext());
+            ex.putSignalingParticipant(getParticipantIdentifier());
+
+            guardianGroup.gthrow(ex, participantList);
+            exceptionThrown = true;
+        } else {
+            setParticipantState(GuardianGroup.SUSPENDED_PARTICIPANT_STATE);
+        }
+    }
+
+    public boolean propagate(GlobalExceptionInterface ex) {
+        //1)Compares the current context with the exception's target context
+        return !getCurrentContext().equals(ex.getTargetContext());
+    }
+
+    public void checkExceptionStatus() throws GlobalException {
+
+        //Blocks until the state be diferent the SUSPENDED_STATE
+        while (participantState == GuardianGroup.SUSPENDED_PARTICIPANT_STATE && exceptionThrown) {
+            System.out.println(getParticipantIdentifier() + ": I am blocked!");
+            try {
+                Thread.sleep(5000);
+            } catch (InterruptedException ex) {
+                Logger.getLogger(GuardianMemberImpl.class.getName()).log(Level.SEVERE, null, ex);
+            }
+        }
+        exceptionThrown = false;
+        System.out.println(getParticipantIdentifier() + ": I am not blocked!");
+
+        GlobalException exc;
+
+        if ((exc = exceptionQueue.peek()) == null) {
+            System.out.println(getParticipantIdentifier() + "#No exception on exception queue");
+            return;
+        }
+
+        //Check if ex.targetContext() matches the participant id
+        //Eg. ex.targetContext(): Main and participant id: Init.Main.Backup -> should thrown the exception
+        //Test if the exception should be thrown in the target context
+        for (Context c : contextList) {
+            if (exc.getTargetContext().equals(c) && (c.equals(Context.INIT_CONTEXT) || c.getExceptionList().contains(exc.getClass()))) {
+                System.out.println(getParticipantIdentifier() + "#Returning an exception");
+                exceptionQueue.poll();
+                throw exc;
+            }
+        }
+
+        return;
+    }
+
+    public String getParticipantIdentifier() {
+        //1) Return the participant identifier -> context list dot separated
+        StringBuffer participantIdentifier = new StringBuffer();
+        participantIdentifier.append(this.id);
+        for (int i = 0; i < contextList.size(); i++) {
+            participantIdentifier.append("." + contextList.get(i).getName());
+        }
+        return participantIdentifier.toString();
+    }
+
+    public void setUniqueParticipantID(int id) {
+        this.id = id;
+    }
+
+    public int getParticipantState() {
+        return participantState;
+    }
+
+    public void setParticipantState(int state) {
+        this.participantState = state;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/RecoveryRulesImpl.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/RecoveryRulesImpl.java
new file mode 100644
index 0000000000..e2fc2f8048
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/RecoveryRulesImpl.java
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.impl;
+
+import org.apache.tuscany.sca.implementation.guardian.RecoveryRules;
+import java.util.Hashtable;
+import java.util.Map;
+import org.apache.axiom.om.OMElement;
+
+public class RecoveryRulesImpl implements RecoveryRules {
+    
+    private Map<String, OMElement> ruleElements = new Hashtable<String, OMElement>();
+
+    public Map<String, OMElement> getRuleElements() {
+        return ruleElements;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/ResolutionTreesImpl.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/ResolutionTreesImpl.java
new file mode 100644
index 0000000000..669f06b1ef
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/impl/ResolutionTreesImpl.java
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.impl;
+
+import java.util.Hashtable;
+import java.util.Map;
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.implementation.guardian.ResolutionTrees;
+
+public class ResolutionTreesImpl implements ResolutionTrees {
+    
+    private Map<String, OMElement> resolutionTreeElements = new Hashtable<String, OMElement>();
+
+    public Map<String, OMElement> getResolutionTreeElements() {
+        return resolutionTreeElements;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupImplementationProvider.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupImplementationProvider.java
new file mode 100644
index 0000000000..2eb3dbdf58
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupImplementationProvider.java
@@ -0,0 +1,115 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.provider;
+
+import org.apache.tuscany.sca.implementation.guardian.impl.*;
+import java.util.Iterator;
+import org.apache.axiom.om.OMAttribute;
+import org.apache.axiom.om.OMElement;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroup;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementation;
+import org.apache.tuscany.sca.interfacedef.Operation;
+import org.apache.tuscany.sca.invocation.Invoker;
+import org.apache.tuscany.sca.provider.ImplementationProvider;
+import org.apache.tuscany.sca.runtime.RuntimeComponent;
+import org.apache.tuscany.sca.runtime.RuntimeComponentService;
+import org.apache.tuscany.sca.implementation.guardian.common.Constants;
+
+public class GuardianGroupImplementationProvider implements ImplementationProvider {
+
+    private GuardianGroupImplementation implementation;
+    private GuardianGroupImpl guardian;
+
+    public GuardianGroupImplementationProvider(RuntimeComponent component, GuardianGroupImplementation implementation) {
+        this.implementation = implementation;
+        this.guardian = createGuardian(implementation.getGuardianProperties());
+    }
+
+    private GuardianGroupImpl createGuardian(OMElement guardianProperties) {
+        GuardianGroupImpl guardian = null;
+
+        String recoveryRules = null;
+        String resolutionTrees = null;
+
+        OMAttribute at;
+        Iterator it = guardianProperties.getAllAttributes();
+        while (it.hasNext()) {
+            at = (OMAttribute) it.next();
+
+            if (at.getLocalName().equals(Constants.RECOVERY_RULES)) {
+                recoveryRules = at.getAttributeValue();
+            } else if (at.getLocalName().equals(Constants.RESOLUTION_TREES)) {
+                resolutionTrees = at.getAttributeValue();
+            }
+        }
+
+        if (recoveryRules != null && resolutionTrees != null) {
+            guardian = new GuardianGroupImpl(recoveryRules, resolutionTrees);
+        }
+
+        return guardian;
+    }
+
+    public void start() {
+    }
+
+    public void stop() {
+    }
+
+    public Invoker createInvoker(RuntimeComponentService service, Operation operation) {
+        String operationName = operation.getName();
+        String interfaceFullName = operation.getInterface().toString();
+
+        //GuardianGroup interface
+        if (interfaceFullName.equals(GuardianGroup.class.getName())) {
+
+            //Why is the createInvoker ivoked 'n' static inner class times?
+            //System.out.println("NAME: " + operationName);
+
+            //public void addGuardianMember(GuardianMember guardianMember)
+            if (operationName.equals("addGuardianMember")) {
+                return new GuardianGroupInvoker.AddGuardianMemberInvoker(guardian);
+            } //public boolean removeGuardianMember(GuardianMember guardianMember)
+            else if (operationName.equals("removeGuardianMember")) {
+                return new GuardianGroupInvoker.RemoveGuardianMemberInvoker(guardian);
+            } //public void enableContext(Context context);
+            else if (operationName.equals("enableContext")) {
+                return new GuardianGroupInvoker.EnableContextInvoker(guardian);
+            } //public void removeContext();
+            else if (operationName.equals("removeContext")) {
+                return new GuardianGroupInvoker.RemoveContextInvoker(guardian);
+            } //public void gthrow(GlobalExceptionInterface ex, List<String> participantList);
+            else if (operationName.equals("gthrow")) {
+                return new GuardianGroupInvoker.GthrowInvoker(guardian);
+            } //public boolean propagate(GlobalExceptionInterface ex);
+            else if (operationName.equals("propagate")) {
+                return new GuardianGroupInvoker.PropagateInvoker(guardian);
+            } //public void checkExceptionStatus() throws GlobalException;
+            else if (operationName.equals("checkExceptionStatus")) {
+                return new GuardianGroupInvoker.CheckExceptionStatusInvoker(guardian);
+            }
+        }
+
+        return new GuardianGroupInvoker(null);
+    }
+
+    public boolean supportsOneWayInvocation() {
+        return false;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupImplementationProviderFactory.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupImplementationProviderFactory.java
new file mode 100644
index 0000000000..a42c35506d
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupImplementationProviderFactory.java
@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.provider;
+
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementation;
+import org.apache.tuscany.sca.provider.ImplementationProvider;
+import org.apache.tuscany.sca.provider.ImplementationProviderFactory;
+import org.apache.tuscany.sca.runtime.RuntimeComponent;
+
+public class GuardianGroupImplementationProviderFactory implements ImplementationProviderFactory<GuardianGroupImplementation> {
+    public GuardianGroupImplementationProviderFactory(ExtensionPointRegistry extensionPoints) {
+    }
+
+    public ImplementationProvider createImplementationProvider(RuntimeComponent component, GuardianGroupImplementation implementation) {
+        return new GuardianGroupImplementationProvider(component, implementation);
+    }
+
+    public Class<GuardianGroupImplementation> getModelType() {
+        return GuardianGroupImplementation.class;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupInvoker.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupInvoker.java
new file mode 100644
index 0000000000..8f393ebcb9
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/provider/GuardianGroupInvoker.java
@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.provider;
+
+import org.apache.tuscany.sca.implementation.guardian.impl.*;
+import java.util.List;
+import org.apache.tuscany.sca.implementation.guardian.GuardianMember;
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalExceptionInterface;
+import org.apache.tuscany.sca.invocation.Invoker;
+import org.apache.tuscany.sca.invocation.Message;
+
+public class GuardianGroupInvoker implements Invoker {
+
+    protected final GuardianGroupImpl guardian;
+
+    public GuardianGroupInvoker(GuardianGroupImpl guardian) {
+        this.guardian = guardian;
+    }
+
+    public Message invoke(Message arg0) {
+        throw new UnsupportedOperationException("Not supported yet. 1");
+    }
+
+    //AddGuardianMember operation invoker
+    public static class AddGuardianMemberInvoker extends GuardianGroupInvoker {
+
+        public AddGuardianMemberInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+
+            GuardianMember guardianMember = (GuardianMember) ((Object[]) msg.getBody())[0];
+            this.guardian.addGuardianMember(guardianMember);
+
+            return msg;
+        }
+    }
+
+    //RemoveGuardianMember operation invoker
+    public static class RemoveGuardianMemberInvoker extends GuardianGroupInvoker {
+
+        public RemoveGuardianMemberInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+
+            GuardianMember guardianMember = (GuardianMember) ((Object[]) msg.getBody())[0];
+            boolean returnedValue = this.guardian.removeGuardianMember(guardianMember);
+
+            msg.setBody(returnedValue);
+            return msg;
+        }
+    }
+
+    //EnableContext operation invoker
+    public static class EnableContextInvoker extends GuardianGroupInvoker {
+
+        public EnableContextInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+
+            Context context = (Context) ((Object[]) msg.getBody())[0];
+
+            this.guardian.enableContext(context);
+
+            return msg;
+        }
+    }
+
+    //RemoveContext operation invoker
+    public static class RemoveContextInvoker extends GuardianGroupInvoker {
+
+        public RemoveContextInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+
+            this.guardian.removeContext();
+
+            return msg;
+        }
+    }
+
+    //Gthrow operation invoker
+    public static class GthrowInvoker extends GuardianGroupInvoker {
+
+        public GthrowInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+
+            GlobalExceptionInterface ex = (GlobalExceptionInterface) ((Object[]) msg.getBody())[0];
+            List<String> participantList = (List<String>) ((Object[]) msg.getBody())[1];
+
+            this.guardian.gthrow(ex, participantList);
+
+            return msg;
+        }
+    }
+
+    //Propagate operation invoker
+    public static class PropagateInvoker extends GuardianGroupInvoker {
+
+        public PropagateInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+            
+            GlobalExceptionInterface ex = (GlobalExceptionInterface) ((Object[]) msg.getBody())[0];
+
+            boolean needPropagation = this.guardian.propagate(ex);
+            msg.setBody(needPropagation);
+
+            return msg;
+        }
+    }
+
+    //CheckExceptionStatus operation invoker
+    public static class CheckExceptionStatusInvoker extends GuardianGroupInvoker {
+
+        public CheckExceptionStatusInvoker(GuardianGroupImpl guardian) {
+            super(guardian);
+        }
+
+        @Override
+        public Message invoke(Message msg) {
+
+            this.guardian.checkExceptionStatus();
+
+            return msg;
+        }
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/GuardianGroupImplementationProcessor.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/GuardianGroupImplementationProcessor.java
new file mode 100644
index 0000000000..048ef7b9c8
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/GuardianGroupImplementationProcessor.java
@@ -0,0 +1,144 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.xml;
+
+import org.apache.tuscany.sca.implementation.guardian.*;
+import java.util.Iterator;
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+import org.apache.axiom.om.OMAbstractFactory;
+import org.apache.axiom.om.OMAttribute;
+import org.apache.axiom.om.OMElement;
+import org.apache.axiom.om.OMFactory;
+import org.apache.tuscany.sca.assembly.AssemblyFactory;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+import org.apache.tuscany.sca.assembly.xml.Constants;
+import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
+import org.apache.tuscany.sca.implementation.guardian.impl.GuardianGroupImplementationFactoryImpl;
+import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceFactory;
+import org.apache.tuscany.sca.monitor.Monitor;
+
+public class GuardianGroupImplementationProcessor implements StAXArtifactProcessor<GuardianGroupImplementation> {
+
+    protected static final QName IMPLEMENTATION_GUARDIAN = new QName(Constants.SCA10_TUSCANY_NS, "implementation.guardian");
+    protected static final QName GUARDIAN_PROPERTIES = new QName(Constants.SCA10_TUSCANY_NS, "guardianProperties");
+    private GuardianGroupImplementationFactory guardianGroupImplementationFactory;
+
+    private AssemblyFactory assemblyFactor;
+    private JavaInterfaceFactory javaFactory;
+
+    //public GuardianGroupImplementationProcessor(ModelFactoryExtensionPoint modelFactories, Monitor monitor) {
+    //public GuardianGroupImplementationProcessor(ModelFactoryExtensionPoint modelFactories) {
+    public GuardianGroupImplementationProcessor(ModelFactoryExtensionPoint modelFactories, Monitor monitor) {
+
+        assemblyFactor = modelFactories.getFactory(AssemblyFactory.class);
+        javaFactory = modelFactories.getFactory(JavaInterfaceFactory.class);
+
+        guardianGroupImplementationFactory = new GuardianGroupImplementationFactoryImpl(assemblyFactor, javaFactory);
+        //guardianGroupImplementationFactory = modelFactories.getFactory(GuardianGroupImplementationFactory.class);
+    }
+
+    public GuardianGroupImplementation read(XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
+        assert IMPLEMENTATION_GUARDIAN.equals(reader.getName());
+
+        GuardianGroupImplementation implementation = guardianGroupImplementationFactory.createGuardianGroupImplementation();
+
+        while (reader.hasNext()) {
+            reader.next();
+
+            if (reader.isStartElement() && reader.getName().equals(GUARDIAN_PROPERTIES)) {
+                OMElement guardianPropertiesElement = readGuardianProperties(reader);
+
+                //REVIEW
+                implementation.setGuardianProperties(guardianPropertiesElement);
+
+                break;
+            }
+        }
+
+        return implementation;
+    }
+
+    private OMElement readGuardianProperties(XMLStreamReader reader) {
+        OMFactory fac = OMAbstractFactory.getOMFactory();
+        OMElement element = fac.createOMElement(reader.getName());
+
+        for (int i = 0; i < reader.getAttributeCount(); i++) {
+
+            String ns = reader.getAttributeNamespace(i);
+            String prefix = reader.getAttributePrefix(i);
+            String qname = reader.getAttributeLocalName(i);
+            String value = reader.getAttributeValue(i);
+
+            if (ns != null) {
+                element.addAttribute(qname, value, fac.createOMNamespace(ns, prefix));
+                element.declareNamespace(ns, prefix);
+            } else {
+                element.addAttribute(qname, value, null);
+            }
+        }
+
+        return element;
+    }
+
+    public void write(GuardianGroupImplementation implementation, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+        writer.writeStartElement(IMPLEMENTATION_GUARDIAN.getNamespaceURI(), IMPLEMENTATION_GUARDIAN.getLocalPart());
+
+        OMElement guardianProperties = implementation.getGuardianProperties();
+        if (guardianProperties != null) {
+            writeGuardianProperties(guardianProperties, writer);
+        }
+
+        writer.writeEndElement();
+    }
+
+    private void writeGuardianProperties(OMElement guardianProperties, XMLStreamWriter writer) throws XMLStreamException {
+
+        OMAttribute at;
+
+        //write the element's name
+        writer.writeStartElement(guardianProperties.getLocalName());
+
+        //write the attributes
+        Iterator attributes = guardianProperties.getAllAttributes();
+        while (attributes.hasNext()) {
+            at = (OMAttribute) attributes.next();
+            writer.writeAttribute(at.getLocalName(), at.getAttributeValue());
+        }
+
+        writer.writeEndElement();
+    }
+
+    public QName getArtifactType() {
+        return IMPLEMENTATION_GUARDIAN;
+    }
+
+    public void resolve(GuardianGroupImplementation arg0, ModelResolver arg1) throws ContributionResolveException {
+    }
+
+    public Class<GuardianGroupImplementation> getModelType() {
+        return GuardianGroupImplementation.class;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/RecoveryRulesProcessor.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/RecoveryRulesProcessor.java
new file mode 100644
index 0000000000..7d82f356de
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/RecoveryRulesProcessor.java
@@ -0,0 +1,158 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.xml;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+import org.apache.axiom.om.OMAbstractFactory;
+import org.apache.axiom.om.OMElement;
+import org.apache.axiom.om.OMFactory;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+import org.apache.tuscany.sca.implementation.guardian.common.Constants;
+import org.apache.tuscany.sca.implementation.guardian.impl.RecoveryRulesImpl;
+import org.apache.tuscany.sca.implementation.guardian.RecoveryRules;
+
+public class RecoveryRulesProcessor implements StAXArtifactProcessor<RecoveryRules>, Constants {
+
+    private static final QName RECOVERY_RULES_POLICY_QNAME = RecoveryRules.RECOVERY_RULES_POLICY_QNAME;
+
+    public RecoveryRulesProcessor() {
+    }
+
+    public RecoveryRules read(XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
+
+        RecoveryRules policy = new RecoveryRulesImpl();
+        QName name = null;
+        String ruleName = null;
+        OMElement ruleElement = null;
+        while (reader.hasNext()) {
+
+            if (reader.isStartElement()) {
+
+                name = reader.getName();
+                if (RULE.equals(name.getLocalPart())) {
+
+                    ruleName = reader.getAttributeValue(null, Constants.NAME);
+                    ruleElement = loadElement(reader);
+
+                    policy.getRuleElements().put(ruleName, ruleElement);
+                }
+            } else if (reader.isEndElement()) {
+                if (RECOVERY_RULES_POLICY_QNAME.equals(reader.getName())) {
+                    break;
+                }
+            }
+
+            reader.next();
+        }
+
+        return policy;
+    }
+
+    public void write(RecoveryRules policy, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+        //throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public QName getArtifactType() {
+        return RECOVERY_RULES_POLICY_QNAME;
+    }
+
+    public void resolve(RecoveryRules arg0, ModelResolver arg1) throws ContributionResolveException {
+        
+    }
+
+    public Class<RecoveryRules> getModelType() {
+        return RecoveryRules.class;
+    }
+
+    private OMElement loadElement(XMLStreamReader reader) throws XMLStreamException {
+        OMFactory fac = OMAbstractFactory.getOMFactory();
+        OMElement head = fac.createOMElement(reader.getName());
+
+        //Load the attributes for the rule tag
+        loadAttributes(reader, head, fac);
+
+        OMElement current = head;
+        while (true) {
+
+            switch (reader.next()) {
+                case XMLStreamConstants.START_ELEMENT:
+
+                    QName name = new QName(reader.getName().getLocalPart());
+                    OMElement child = fac.createOMElement(name, current);
+
+                    int count = reader.getNamespaceCount();
+                    for (int i = 0; i < count; i++) {
+                        String prefix = reader.getNamespacePrefix(i);
+                        String ns = reader.getNamespaceURI(i);
+                        child.declareNamespace(ns, prefix);
+                    }
+
+                    if (!"".equals(name.getNamespaceURI())) {
+                        child.declareNamespace(name.getNamespaceURI(), name.getPrefix());
+                    }
+
+                    // add the attributes for this element
+                    loadAttributes(reader, child, fac);
+                    current = child;
+                    break;
+                case XMLStreamConstants.CDATA:
+                    fac.createOMText(current, reader.getText());
+                    break;
+                case XMLStreamConstants.CHARACTERS:
+                    String text = reader.getText().trim();
+                    if (text.length() != 0) {
+                        fac.createOMText(current, reader.getText());
+                    }
+                    break;
+                case XMLStreamConstants.END_ELEMENT:
+                    if (current == head) {
+                        return head;
+                    } else {
+                        current = (OMElement) current.getParent();
+                    }
+            }
+        }
+    }
+
+    private void loadAttributes(XMLStreamReader reader, OMElement elem, OMFactory fac) {
+        int count = reader.getAttributeCount();
+        for (int i = 0; i < count; i++) {
+            String ns = reader.getAttributeNamespace(i);
+            String prefix = reader.getAttributePrefix(i);
+            String qname = reader.getAttributeLocalName(i);
+            String value = reader.getAttributeValue(i);
+
+            if (ns != null) {
+                elem.addAttribute(qname, value, fac.createOMNamespace(ns, prefix));
+                elem.declareNamespace(ns, prefix);
+            } else {
+                elem.addAttribute(qname, value, null);
+            }
+        }
+    }
+
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/ResolutionTreesProcessor.java b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/ResolutionTreesProcessor.java
new file mode 100644
index 0000000000..b9cfe647b4
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/java/org/apache/tuscany/sca/implementation/guardian/xml/ResolutionTreesProcessor.java
@@ -0,0 +1,157 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.xml;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+import org.apache.axiom.om.OMAbstractFactory;
+import org.apache.axiom.om.OMElement;
+import org.apache.axiom.om.OMFactory;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+import org.apache.tuscany.sca.implementation.guardian.common.Constants;
+import org.apache.tuscany.sca.implementation.guardian.impl.ResolutionTreesImpl;
+import org.apache.tuscany.sca.implementation.guardian.ResolutionTrees;
+
+public class ResolutionTreesProcessor implements StAXArtifactProcessor<ResolutionTrees>, Constants {
+
+    private static final QName RESOLUTION_TREES_POLICY_QNAME = ResolutionTrees.RESOLUTION_TREES_POLICY_QNAME;
+
+    public ResolutionTreesProcessor() {
+    }
+
+    public ResolutionTrees read(XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
+
+        ResolutionTrees policy = new ResolutionTreesImpl();
+        QName name = null;
+        String ruleName = null;
+        OMElement ruleElement = null;
+        while (reader.hasNext()) {
+
+            if (reader.isStartElement()) {
+
+                name = reader.getName();
+                if (RESOLUTION_TREE.equals(name.getLocalPart())) {
+
+                    ruleName = reader.getAttributeValue(null, Constants.EXCEPTION_LEVEL);
+                    ruleElement = loadElement(reader);
+
+                    policy.getResolutionTreeElements().put(ruleName, ruleElement);
+                }
+            } else if (reader.isEndElement()) {
+                if (RESOLUTION_TREES_POLICY_QNAME.equals(reader.getName())) {
+                    break;
+                }
+            }
+
+            reader.next();
+        }
+
+        return policy;
+    }
+
+    public void write(ResolutionTrees policy, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+        //throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public QName getArtifactType() {
+        return RESOLUTION_TREES_POLICY_QNAME;
+    }
+
+    public void resolve(ResolutionTrees arg0, ModelResolver arg1) throws ContributionResolveException {
+        //throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public Class<ResolutionTrees> getModelType() {
+        return ResolutionTrees.class;
+    }
+
+    private OMElement loadElement(XMLStreamReader reader) throws XMLStreamException {
+        OMFactory fac = OMAbstractFactory.getOMFactory();
+        OMElement head = fac.createOMElement(reader.getName());
+
+        //Load the attributes for the rule tag
+        loadAttributes(reader, head, fac);
+
+        OMElement current = head;
+        while (true) {
+
+            switch (reader.next()) {
+                case XMLStreamConstants.START_ELEMENT:
+
+                    QName name = new QName(reader.getName().getLocalPart());
+                    OMElement child = fac.createOMElement(name, current);
+
+                    int count = reader.getNamespaceCount();
+                    for (int i = 0; i < count; i++) {
+                        String prefix = reader.getNamespacePrefix(i);
+                        String ns = reader.getNamespaceURI(i);
+                        child.declareNamespace(ns, prefix);
+                    }
+
+                    if (!"".equals(name.getNamespaceURI())) {
+                        child.declareNamespace(name.getNamespaceURI(), name.getPrefix());
+                    }
+
+                    // add the attributes for this element
+                    loadAttributes(reader, child, fac);
+                    current = child;
+                    break;
+                case XMLStreamConstants.CDATA:
+                    fac.createOMText(current, reader.getText());
+                    break;
+                case XMLStreamConstants.CHARACTERS:
+                    String text = reader.getText().trim();
+                    if (text.length() != 0) {
+                        fac.createOMText(current, reader.getText());
+                    }
+                    break;
+                case XMLStreamConstants.END_ELEMENT:
+                    if (current == head) {
+                        return head;
+                    } else {
+                        current = (OMElement) current.getParent();
+                    }
+            }
+        }
+    }
+
+    private void loadAttributes(XMLStreamReader reader, OMElement elem, OMFactory fac) {
+        int count = reader.getAttributeCount();
+        for (int i = 0; i < count; i++) {
+            String ns = reader.getAttributeNamespace(i);
+            String prefix = reader.getAttributePrefix(i);
+            String qname = reader.getAttributeLocalName(i);
+            String value = reader.getAttributeValue(i);
+
+            if (ns != null) {
+                elem.addAttribute(qname, value, fac.createOMNamespace(ns, prefix));
+                elem.declareNamespace(ns, prefix);
+            } else {
+                elem.addAttribute(qname, value, null);
+            }
+        }
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor b/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor
new file mode 100644
index 0000000000..b489bb90fc
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor
@@ -0,0 +1,19 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+# 
+#   http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License. 
+
+# Implementation class for the artifact processor extension
+org.apache.tuscany.sca.implementation.guardian.xml.GuardianGroupImplementationProcessor;qname=http://tuscany.apache.org/xmlns/sca/1.0#implementation.guardian,model=org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementation,factory=org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementationFactory
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementationFactory b/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementationFactory
new file mode 100644
index 0000000000..744815a572
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementationFactory
@@ -0,0 +1,19 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+# Implementation class for implementation model factory
+org.apache.tuscany.sca.implementation.guardian.impl.GuardianGroupImplementationFactoryImpl
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.provider.ImplementationProviderFactory b/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.provider.ImplementationProviderFactory
new file mode 100644
index 0000000000..4ab8d2e6a3
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/META-INF/services/org.apache.tuscany.sca.provider.ImplementationProviderFactory
@@ -0,0 +1,19 @@
+# Licensed to the Apache Software Foundation (ASF) under one

+# or more contributor license agreements.  See the NOTICE file

+# distributed with this work for additional information

+# regarding copyright ownership.  The ASF licenses this file

+# to you under the Apache License, Version 2.0 (the

+# "License"); you may not use this file except in compliance

+# with the License.  You may obtain a copy of the License at

+# 

+#   http://www.apache.org/licenses/LICENSE-2.0

+# 

+# Unless required by applicable law or agreed to in writing,

+# software distributed under the License is distributed on an

+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

+# KIND, either express or implied.  See the License for the

+# specific language governing permissions and limitations

+# under the License. 

+

+# Implementation class for the implementation extension

+org.apache.tuscany.sca.implementation.guardian.provider.GuardianGroupImplementationProviderFactory;model=org.apache.tuscany.sca.implementation.guardian.GuardianGroupImplementation

diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/guardianTest.composite b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/guardianTest.composite
new file mode 100644
index 0000000000..d31485d67c
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/guardianTest.composite
@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+    * Licensed to the Apache Software Foundation (ASF) under one
+    * or more contributor license agreements.  See the NOTICE file
+    * distributed with this work for additional information
+    * regarding copyright ownership.  The ASF licenses this file
+    * to you under the Apache License, Version 2.0 (the
+    * "License"); you may not use this file except in compliance
+    * with the License.  You may obtain a copy of the License at
+    *
+    *   http://www.apache.org/licenses/LICENSE-2.0
+    *
+    * Unless required by applicable law or agreed to in writing,
+    * software distributed under the License is distributed on an
+    * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    * KIND, either express or implied.  See the License for the
+    * specific language governing permissions and limitations
+    * under the License.
+-->
+
+<composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
+    xmlns:tuscany="http://tuscany.apache.org/xmlns/sca/1.0"
+	targetNamespace="http://guardianTest"
+	name="guardianTest">
+
+	<component name="GuardianComponent">
+		<tuscany:implementation.guardian>
+
+			<tuscany:guardianProperties
+				recovery_rules="src/main/resources/recoveryrules_nbackpus_concurrent.xml"
+				resolution_trees="src/main/resources/resolutionTree.xml"/>
+
+		</tuscany:implementation.guardian>
+	</component>
+
+</composite>
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/primaryBackup.composite b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/primaryBackup.composite
new file mode 100644
index 0000000000..fcb78e3879
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/primaryBackup.composite
@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (thea
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+-->
+
+<composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
+    xmlns:tuscany="http://tuscany.apache.org/xmlns/sca/1.0"
+	targetNamespace="http://guardianTest"
+	name="guardianTest">
+
+	<component name="Participant1">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember1"/>
+		<reference name="nodes" target="Participant2 Participant3 Participant4"/>
+	</component>  
+
+	<component name="Participant2">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember2"/>
+		<reference name="nodes" target="Participant1 Participant3 Participant4"/>
+	</component>  
+
+	<component name="Participant3">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember3"/>
+		<reference name="nodes" target="Participant1 Participant2 Participant4"/>
+	</component>  
+
+	<component name="Participant4">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember4"/>
+		<reference name="nodes" target="Participant1 Participant2 Participant3"/>
+	</component>  
+
+	<component name="GuardianMember1">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianComponent"/> 
+	</component> 
+
+	<component name="GuardianMember2">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianComponent"/> 
+	</component> 
+
+	<component name="GuardianMember3">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianComponent"/> 
+	</component> 
+
+	<component name="GuardianMember4">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianComponent"/> 
+	</component> 
+
+	<component name="GuardianComponent">
+		<tuscany:implementation.guardian>
+
+			<tuscany:guardianProperties
+				recovery_rules="src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/recoveryRules.xml"
+				resolution_trees="src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/resolutionTrees.xml"/>
+
+		</tuscany:implementation.guardian>
+
+	</component> 
+
+</composite>
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/recoveryRules.xml b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/recoveryRules.xml
new file mode 100644
index 0000000000..b2eacf8b8a
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/recoveryRules.xml
@@ -0,0 +1,82 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (thea
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+-->
+
+<recovery_rules>
+
+	<!-- A new participant joins in the group -->
+	<rule name="Rule1" signaled_exception="org.apache.tuscany.sca.implementation.guardian.common.JoinException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupJoinedException" target_context="PRIMARY"/>
+		</participant>
+
+		<participant match="SIGNALER">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryExistsException" target_context="MAIN" min_participant_joined="2"/>
+		</participant>	
+	</rule>
+
+	<!-- The Primary fails -->
+	<rule name="Rule2" signaled_exception="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException" target_context="INIT_CONTEXT"/>
+		</participant>
+
+		<participant match="*.BACKUP">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException" target_context="MAIN">
+				<affected_participants>FIRST</affected_participants>
+			</throw_exception>
+		</participant>
+	</rule>
+
+	<!-- The Backup fails -->
+	<rule name="Rule3" signaled_exception="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException" target_context="PRIMARY"/>
+		</participant>
+
+		<participant match="SIGNALER">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException" target_context="INIT_CONTEXT"/>
+		</participant>
+	</rule>	
+
+	<!-- The Primary and Backup fail together -->
+	<rule  name="Rule4" signaled_exception="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryBackupFailedTogetherException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException" target_context="INIT_CONTEXT"/>
+		</participant>
+		
+		 <!-- Backup signaler -->
+		<participant match="*.BACKUP,SIGNALER">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException" target_context="INIT_CONTEXT"/>
+		</participant>		
+
+		<!-- Excluding the backup signaler -->
+		<participant match="*.BACKUP,!SIGNALER"> 
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException" target_context="MAIN">
+				<affected_participants>FIRST</affected_participants>
+			</throw_exception>
+		</participant>		
+
+	</rule>
+
+</recovery_rules>
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/resolutionTrees.xml b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/resolutionTrees.xml
new file mode 100644
index 0000000000..ca3fa1534c
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/resolutionTrees.xml
@@ -0,0 +1,8 @@
+<resolution_trees>
+	<resolution_tree exception_level="1">
+		<exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryBackupFailedTogetherException">
+			<exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException"/>
+			<exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException"/>
+		</exception>
+	</resolution_tree>
+</resolution_trees>
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/primaryBackup.composite b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/primaryBackup.composite
new file mode 100644
index 0000000000..85af4efd48
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/primaryBackup.composite
@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (thea
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+-->
+<composite	xmlns="http://www.osoa.org/xmlns/sca/1.0"
+    xmlns:tuscany="http://tuscany.apache.org/xmlns/sca/1.0"
+	targetNamespace="http://guardianTest"
+	name="guardianTest">
+
+	<component name="Participant1">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember1"/>
+		<reference name="nodes" target="Participant2"/>
+	</component>  
+
+	<component name="Participant2">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember2"/>
+		<reference name="nodes" target="Participant1"/>
+	</component>  
+
+	<component name="GuardianMember1">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianComponent"/> 
+	</component> 
+
+	<component name="GuardianMember2">
+		<implementation.java class="org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianComponent"/> 
+	</component> 
+
+	<component name="GuardianComponent">
+		<tuscany:implementation.guardian>
+
+			<tuscany:guardianProperties
+				recovery_rules="src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/recoveryRules.xml"
+				resolution_trees="src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/resolutionTrees.xml"/>
+
+		</tuscany:implementation.guardian>
+
+	</component> 
+
+</composite>
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/recoveryRules.xml b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/recoveryRules.xml
new file mode 100644
index 0000000000..0016fa4d9f
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/recoveryRules.xml
@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (thea
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+-->
+
+<recovery_rules>
+
+	<rule name="Rule1" signaled_exception="org.apache.tuscany.sca.implementation.guardian.common.JoinException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupJoinedException" target_context="PRIMARY"/>
+		</participant>
+
+		<participant match="SIGNALER">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryExistsException" target_context="MAIN" min_participant_joined="2"/>
+		</participant>		
+	</rule>
+
+	<rule name="Rule2" signaled_exception="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException" target_context="INIT_CONTEXT"/>
+		</participant>
+
+		<participant match="*.BACKUP">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.PrimaryFailedException" target_context="MAIN"/>
+		</participant>
+	</rule>
+
+	<rule name="Rule3" signaled_exception="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException">
+
+		<participant match="*.PRIMARY">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException" target_context="PRIMARY"/>
+		</participant>
+
+		<participant match="*.BACKUP">
+			<throw_exception class="org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.BackupFailedException" target_context="INIT_CONTEXT"/>
+		</participant>
+	</rule>	
+
+</recovery_rules>
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/lcaTest.xml b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/lcaTest.xml
new file mode 100644
index 0000000000..e528760ad8
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/org/apache/tuscany/sca/implementation/guardian/lcaTest.xml
@@ -0,0 +1,21 @@
+<resolution_trees>
+	<resolution_tree exception_level="1">
+		<exception class="Exception1">
+			<exception class="Exception2">
+				<exception class="Exception4"/>
+				<exception class="Exception5"/>
+			</exception>
+			<exception class="Exception3">
+				<exception class="Exception6"/>
+				<exception class="Exception7"/>
+				<exception class="Exception8"/>
+			</exception>
+		</exception>
+	</resolution_tree>
+</resolution_trees>
+
+
+
+
+
+
diff --git a/sandbox/dougsleite/implementation-guardian/src/main/resources/resources.tar.gz b/sandbox/dougsleite/implementation-guardian/src/main/resources/resources.tar.gz
new file mode 100644
index 0000000000..8845a544fe
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/main/resources/resources.tar.gz
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/GuardianImplementationTest.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/GuardianImplementationTest.java
new file mode 100644
index 0000000000..ba4f6230d8
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/GuardianImplementationTest.java
@@ -0,0 +1,77 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import org.apache.tuscany.sca.implementation.guardian.*;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+import org.apache.tuscany.sca.implementation.guardian.impl.GuardianMemberImpl;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class GuardianImplementationTest {
+
+//    private SCADomain scaDomain;
+//    private GuardianGroup guardian;
+//
+//    @Before
+//    public void init() throws Exception {
+//        scaDomain = SCADomain.newInstance("org/apache/tuscany/sca/implementation/guardian/guardianTest.composite");
+//        guardian = scaDomain.getService(GuardianGroup.class, "GuardianComponent");
+//    }
+//
+//    @Test
+//    public void enabelContextTest() throws Exception {
+//        guardian.enableContext(Context.INIT_CONTEXT);
+//    }
+//
+//    @After
+//    public void destroy() {
+//        scaDomain.close();
+//    }
+    public static void main(String... args) {
+
+        SCADomain scaDomain = SCADomain.newInstance("org/apache/tuscany/sca/implementation/guardian/guardianTest.composite");
+        GuardianGroup guardian = scaDomain.getService(GuardianGroup.class, "GuardianComponent");
+
+        System.out.println("\n#EnableContext invocation");
+        guardian.enableContext(Context.INIT_CONTEXT);
+
+        System.out.println("\n#RemoveContext invocation");
+        guardian.removeContext();
+
+        System.out.println("\n#CheckExceptionStatus invocation");
+        guardian.checkExceptionStatus();
+
+        System.out.println("\n#CheckExceptionStatus invocation");
+        boolean value = guardian.propagate(new GlobalException());
+        System.out.println("returned value: " + value);
+
+        System.out.println("\n#AddGuardianMember invocation");
+        guardian.addGuardianMember(new GuardianMemberImpl());
+
+        System.out.println("\n#RemoveGuardianMember invocation");
+        value = guardian.removeGuardianMember(new GuardianMemberImpl());
+        System.out.println("returned value: " + value);
+
+    }
+
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/LCATestCase.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/LCATestCase.java
new file mode 100644
index 0000000000..3c5e6b1b19
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/LCATestCase.java
@@ -0,0 +1,115 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian;
+
+import java.io.FileInputStream;
+import org.apache.tuscany.sca.implementation.guardian.common.ResolutionTreeUtils;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.Map;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamReader;
+import org.junit.Test;
+import org.apache.axiom.om.OMElement;
+import java.util.List;
+import junit.framework.Assert;
+import org.apache.tuscany.sca.implementation.guardian.xml.ResolutionTreesProcessor;
+import org.junit.Before;
+
+public class LCATestCase {
+
+    private ResolutionTreeUtils treeUtils;
+
+    @Before
+    public void init() throws Exception {
+        ResolutionTreesProcessor processor = new ResolutionTreesProcessor();
+
+        FileInputStream fileInputStream = new FileInputStream("src/main/resources/org/apache/" +
+                "tuscany/sca/implementation/guardian/lcaTest.xml");
+        XMLStreamReader reader = XMLInputFactory.newInstance().createXMLStreamReader(fileInputStream);
+
+
+        ResolutionTrees policy = processor.read(reader);
+        Map<String, OMElement> resolutionTrees = policy.getResolutionTreeElements();
+
+        List<OMElement> rootElements = getRootElements(resolutionTrees.values());
+
+        treeUtils = new ResolutionTreeUtils();
+        treeUtils.setRoot(rootElements.get(0));
+    }
+
+    @Test
+    public void testLCAEx2Ex2() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception2", "Exception2");
+        System.out.println("lca: " + lca);
+        Assert.assertEquals("Exception2", lca);
+    }
+
+    @Test
+    public void testLCAEx2Ex3() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception2", "Exception3");
+        Assert.assertEquals("Exception1", lca);
+    }
+
+    @Test
+    public void testLCAEx2Ex8() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception2", "Exception8");
+        Assert.assertEquals("Exception1", lca);
+    }
+
+    @Test
+    public void testLCAEx4Ex3() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception4", "Exception3");
+        Assert.assertEquals("Exception1", lca);
+    }
+
+    @Test
+    public void testLCAEx4Ex5() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception4", "Exception5");
+        Assert.assertEquals("Exception2", lca);
+    }
+
+    @Test
+    public void testLCAEx6Ex7() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception6", "Exception7");
+        Assert.assertEquals("Exception3", lca);
+    }
+
+    @Test
+    public void testLCAEx1Ex8() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception1", "Exception8");
+        Assert.assertEquals("Exception1", lca);
+    }
+
+    @Test
+    public void testLCAEx2Ex5() throws Exception {
+        String lca = treeUtils.getLowestCommonAncestor("Exception2", "Exception5");
+        Assert.assertEquals("Exception2", lca);
+    }
+
+    private List<OMElement> getRootElements(Collection<OMElement> resolutionTrees) {
+        List<OMElement> rootElements = new LinkedList<OMElement>();
+
+        for (OMElement resolutionTree : resolutionTrees) {
+            rootElements.add(resolutionTree.getFirstElement());
+        }
+
+        return rootElements;
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/ApplyUpdateFailureException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/ApplyUpdateFailureException.java
new file mode 100644
index 0000000000..b08b26942d
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/ApplyUpdateFailureException.java
@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+public class ApplyUpdateFailureException extends RuntimeException {
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/BackupFailedException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/BackupFailedException.java
new file mode 100644
index 0000000000..25adf1d739
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/BackupFailedException.java
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public class BackupFailedException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/BackupJoinedException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/BackupJoinedException.java
new file mode 100644
index 0000000000..f0d29f461f
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/BackupJoinedException.java
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public class BackupJoinedException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/Node.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/Node.java
new file mode 100644
index 0000000000..6aa9456816
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/Node.java
@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.osoa.sca.annotations.OneWay;
+
+public interface Node {
+
+    @OneWay
+    public void execute();
+
+    public void sendUpdate(String s);
+
+    public void applyUpdate();
+
+    public String getID();
+
+    public void kill();
+
+    public boolean isDead();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/NodeImpl.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/NodeImpl.java
new file mode 100644
index 0000000000..37f4f529f0
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/NodeImpl.java
@@ -0,0 +1,282 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.apache.tuscany.sca.implementation.guardian.GuardianMember;
+import org.apache.tuscany.sca.implementation.guardian.common.Context;
+import org.osoa.sca.annotations.Init;
+import org.osoa.sca.annotations.Reference;
+import org.osoa.sca.annotations.Scope;
+import org.osoa.sca.annotations.OneWay;
+
+@Scope("COMPOSITE")
+public class NodeImpl implements Node, TestInterface {
+
+    private static int PRIMARY = 0;
+    private static int BACKUP = 1;
+    private boolean isDead;
+    private Context mainContext;
+    private Context primaryContext;
+    private Context backupContext;
+    private int role;
+    private String pID;
+    private Queue<String> updates;
+    @Reference(name = "guardian_member", required = true)
+    public GuardianMember gm;
+    @Reference(name = "nodes", required = true)
+    public List<Node> nodeList;
+    private boolean forcePSFException;
+    private boolean forceAUFException;
+    private int upcount;
+
+    public NodeImpl() {
+
+        mainContext = new Context("MAIN");
+        mainContext.addException(PrimaryFailedException.class);
+        mainContext.addException(PrimaryExistsException.class);
+
+        primaryContext = new Context("PRIMARY");
+        primaryContext.addException(BackupFailedException.class);
+        primaryContext.addException(BackupJoinedException.class);
+        primaryContext.addException(PrimaryServiceFailureException.class);
+
+        backupContext = new Context("BACKUP", null);
+
+        updates = new LinkedList();
+
+        isDead = true;
+
+        nodeList = new LinkedList<Node>();
+
+        forcePSFException = false;
+        forceAUFException = false;
+    }
+
+    @Init
+    public void init() {
+        pID = gm.getParticipantIdentifier();
+    }
+
+    @OneWay
+    public void execute() {
+        isDead = false;
+        gm.enableContext(mainContext);
+        role = PRIMARY;
+
+        while (true) {
+
+            //blockingCheck();
+
+            try {
+                System.out.println(pID + "#Main context: ");
+                sleep(pID + "#Sleeping at main context...", 4000);
+
+                gm.checkExceptionStatus();
+
+                if (role == PRIMARY) {
+                    //Config as primary then...
+                    primaryService();
+                } else {
+                    //Config as backup then...
+                    backupService();
+                }
+
+
+            } catch (PrimaryExistsException ex) {
+                System.out.println(pID + "# Exception captured!: PrimaryExistsException");
+                role = BACKUP;
+                
+            } catch (PrimaryFailedException ex) {
+                System.out.println(pID + "# Exception captured!: PrimaryFailedException");
+                System.out.println(pID + "#Needs propagation?: " + gm.propagate(ex));
+
+                if (gm.propagate(ex)) {
+                    //throw ex;
+                    this.kill();
+                    ex.printStackTrace();
+                    return;
+                }
+
+                role = PRIMARY;
+
+            } catch (BackupFailedException ex) {
+                System.out.println(pID + "# Exception captured!: BackupFailedException");
+                System.out.println(pID + "#Needs propagation?: " + gm.propagate(ex));
+
+                if (gm.propagate(ex)) {
+                    //throw ex;
+                    this.kill();
+                    ex.printStackTrace();
+                    return;
+                }
+            }
+        }
+    }
+
+    private void primaryService() {
+        boolean backupAvailable = isThereBackupAvailable();
+
+        upcount = 1;
+
+        while (true) {
+
+            gm.enableContext(primaryContext);
+
+            //blockingCheck();
+
+            try {
+                System.out.println(pID + "#Primary context: ");
+                sleep(pID + "#Sleeping at primary context...", 4000);
+                gm.checkExceptionStatus();
+
+                //Process the request then...
+                System.out.println(pID + "#Processing the request...");
+
+                //Check for an internal error
+                if (forcePSFException) {
+                    throw new PrimaryServiceFailureException();
+                }
+
+                if (backupAvailable) {
+
+                    if (!updateBackups()) {
+                        backupAvailable = isThereBackupAvailable();
+                    }
+
+                } else {
+                    System.out.println(pID + "#No backup available to send updates!");
+                    //backupAvailable = isThereBackupAvailable();
+                }
+                //send the reply to the client
+                System.out.println(pID + "#Sending the reply to the client...");
+
+            } catch (PrimaryServiceFailureException ex) {
+                System.out.println(pID + "# Exception captured!: PrimaryServiceFailureException");
+                gm.gthrow(new PrimaryFailedException(), null);
+            } catch (BackupFailedException ex) {
+                System.out.println(pID + "# Exception captured!: BackupFailedException");
+                //backupAvailable = false;
+                backupAvailable = isThereBackupAvailable();
+            } catch (BackupJoinedException ex) {
+                System.out.println(pID + "# Exception captured!: BackupJoinedException");
+                backupAvailable = true;
+            } finally {
+                gm.removeContext();
+            }
+        }
+    }
+
+    private boolean updateBackups() {
+        boolean flag = false;
+
+        for (Node n : nodeList) {
+            if (!n.isDead()) {
+                n.sendUpdate("Update " + upcount);
+                flag = true;
+            }
+        }
+        if (flag) {
+            upcount++;
+        }
+
+        return flag;
+    }
+
+    private void backupService() {
+        while (true) {
+
+            gm.enableContext(backupContext);
+
+            //blockingCheck();
+
+            try {
+                System.out.println(pID + "#Backup context: ");
+                sleep(pID + "#Sleeping at backup service", 4000);
+                gm.checkExceptionStatus();
+
+                applyUpdate();
+
+                if (forceAUFException) {
+                    throw new ApplyUpdateFailureException();
+                }
+
+            } catch (ApplyUpdateFailureException ex) {
+                System.out.println(pID + "# Exception captured!: ApplyUpdateFailureException");
+                gm.gthrow(new BackupFailedException(), null);
+            } finally {
+                gm.removeContext();
+            }
+        }
+    }
+
+    public String getID() {
+        return gm.getParticipantIdentifier();
+    }
+
+    private void sleep(String msg, int millis) {
+        try {
+            System.out.println(msg);
+            Thread.sleep(millis);
+        } catch (InterruptedException ex) {
+            Logger.getLogger(NodeImpl.class.getName()).log(Level.SEVERE, null, ex);
+        }
+    }
+
+    private boolean isThereBackupAvailable() {
+        for (Node n : nodeList) {
+            if (!n.isDead()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void kill() {
+        isDead = true;
+    }
+
+    public boolean isDead() {
+        return isDead;
+    }
+
+    public void sendUpdate(String update) {
+        System.out.println(pID + "#Receiving updates from primary: " + update);
+        updates.offer(update);
+    }
+
+    public void applyUpdate() {
+        if (!updates.isEmpty()) {
+            System.out.println(pID + "#Applying the updates received from the primary: " + updates.poll());
+        }
+    }
+
+    public void forcePrimaryServiceFailureException() {
+        forcePSFException = true;
+    }
+
+    public void forceApplyUpdateFailureException() {
+        forceAUFException = true;
+    }
+}
+
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryBackupFailedTogetherException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryBackupFailedTogetherException.java
new file mode 100644
index 0000000000..5521caa550
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryBackupFailedTogetherException.java
@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public class PrimaryBackupFailedTogetherException extends GlobalException {
+
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryExistsException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryExistsException.java
new file mode 100644
index 0000000000..d6297a1012
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryExistsException.java
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public class PrimaryExistsException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryFailedException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryFailedException.java
new file mode 100644
index 0000000000..cc1715d077
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryFailedException.java
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public class PrimaryFailedException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryServiceFailureException.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryServiceFailureException.java
new file mode 100644
index 0000000000..0bcfb72bc8
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/PrimaryServiceFailureException.java
@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+import org.apache.tuscany.sca.implementation.guardian.common.GlobalException;
+
+public class PrimaryServiceFailureException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/TestInterface.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/TestInterface.java
new file mode 100644
index 0000000000..7e7bd35cd2
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/common/TestInterface.java
@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common;
+
+public interface TestInterface {
+
+    public void forcePrimaryServiceFailureException();
+
+    public void forceApplyUpdateFailureException();
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/Launch.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/Launch.java
new file mode 100644
index 0000000000..ab0c21dba6
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/concurrentExceptions/Launch.java
@@ -0,0 +1,69 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.concurrentExceptions;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.Node;
+import org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.TestInterface;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class Launch {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("org/apache/tuscany/sca/" +
+                "implementation/guardian/itests/primaryBackup/" +
+                "concurrentExceptions/primaryBackup.composite");
+
+        System.out.println("Starting participat1...");
+        Node c = scaDomain.getService(Node.class, "Participant1");
+        c.execute();
+
+        System.in.read();
+
+        System.out.println("Starting participant2...");
+        Node c2 = scaDomain.getService(Node.class, "Participant2");
+        c2.execute();
+
+        System.in.read();
+
+        System.out.println("Starting participant3...");
+        Node c3 = scaDomain.getService(Node.class, "Participant3");
+        c3.execute();
+
+        System.in.read();
+
+        System.out.println("Starting participant4...");
+        Node c4 = scaDomain.getService(Node.class, "Participant4");
+        c4.execute();
+
+        System.in.read();
+
+        System.out.println("Forcing exception ocurrence at participant1...");
+        TestInterface t = scaDomain.getService(TestInterface.class, "Participant1");
+        t.forcePrimaryServiceFailureException();
+
+        System.out.println("Forcing exception ocurrence at participant2...");
+        TestInterface t2 = scaDomain.getService(TestInterface.class, "Participant2");
+        t2.forceApplyUpdateFailureException();
+
+        System.in.read();
+
+        scaDomain.close();
+    }
+}
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/Launch.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/Launch.java
new file mode 100644
index 0000000000..86df9bc5f9
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/Launch.java
@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.simple;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.Node;
+import org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.TestInterface;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class Launch {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("org/apache/tuscany/sca/" +
+                "implementation/guardian/itests/primaryBackup/" +
+                "simple/primaryBackup.composite");
+
+        System.out.println("Starting participat1...");
+        Node c = scaDomain.getService(Node.class, "Participant1");
+        c.execute();
+
+        System.in.read();
+
+        System.out.println("Starting participant2...");
+        Node c2 = scaDomain.getService(Node.class, "Participant2");
+        c2.execute();
+
+        System.in.read();
+
+        System.out.println("Forcing exception ocurrence at participant1...");
+        TestInterface t = scaDomain.getService(TestInterface.class, "Participant1");
+        t.forcePrimaryServiceFailureException();
+        
+
+        System.in.read();
+
+        scaDomain.close();
+    }
+}
+
diff --git a/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/Launch2.java b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/Launch2.java
new file mode 100644
index 0000000000..1c5fd26745
--- /dev/null
+++ b/sandbox/dougsleite/implementation-guardian/src/test/java/org/apache/tuscany/sca/implementation/guardian/itests/primaryBackup/simple/Launch2.java
@@ -0,0 +1,54 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.simple;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+import org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.Node;
+import org.apache.tuscany.sca.implementation.guardian.itests.primaryBackup.common.TestInterface;
+
+public class Launch2 {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("org/apache/tuscany/sca/" +
+                "implementation/guardian/itests/primaryBackup/" +
+                "simple/primaryBackup.composite");
+
+        System.out.println("Starting participat1...");
+        Node c = scaDomain.getService(Node.class, "Participant1");
+        c.execute();
+
+        System.in.read();
+
+        System.out.println("Starting participant2...");
+        Node c2 = scaDomain.getService(Node.class, "Participant2");
+        c2.execute();
+
+        System.in.read();
+
+        System.out.println("Forcing exception ocurrence at participant2...");
+        TestInterface t = scaDomain.getService(TestInterface.class, "Participant2");
+        t.forceApplyUpdateFailureException();
+
+        System.in.read();
+
+        scaDomain.close();
+    }
+}
+