git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@776434 13f79535-47bb-0310-9956-ffa450edef68

30 files changed, 1714 insertions, 0 deletions

diff --git a/sandbox/dougsleite/guardian-model/.classpath b/sandbox/dougsleite/guardian-model/.classpath
new file mode 100644
index 0000000000..8b0ba27bfa
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/.classpath
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry including="**/*.java" kind="src" output="target/test-classes" path="src/test/java"/>
+	<classpathentry including="**/*.java" kind="src" path="src/main/java"/>
+	<classpathentry kind="con" path="org.devzuz.q.maven.jdt.core.mavenClasspathContainer"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
+	<classpathentry kind="output" path="target/classes"/>
+</classpath>
diff --git a/sandbox/dougsleite/guardian-model/.project b/sandbox/dougsleite/guardian-model/.project
new file mode 100644
index 0000000000..2383adb712
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/.project
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>guardian-model</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.devzuz.q.maven.jdt.core.mavenIncrementalBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+		<nature>org.devzuz.q.maven.jdt.core.mavenNature</nature>
+	</natures>
+</projectDescription>
diff --git a/sandbox/dougsleite/guardian-model/pom.xml b/sandbox/dougsleite/guardian-model/pom.xml
new file mode 100644
index 0000000000..82a1bd5c87
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/pom.xml
@@ -0,0 +1,100 @@
+<?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.    
+--><project>
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.apache.tuscany.sca</groupId>
+        <artifactId>tuscany-sca</artifactId>
+        <version>1.5-SNAPSHOT</version>
+        <relativePath>../../pom.xml</relativePath>
+    </parent>
+    <artifactId>tuscany-guardian-model</artifactId>
+    <name>Guardian Model</name>
+
+    <repositories>
+       <repository>
+          <id>apache.incubator</id>
+          <url>http://people.apache.org/repo/m2-incubating-repository</url>
+       </repository>
+    </repositories>
+
+    <version>1.5-SNAPSHOT</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.tuscany.sca</groupId>
+            <artifactId>tuscany-node-impl</artifactId>
+            <version>1.5-SNAPSHOT</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.tuscany.sca</groupId>
+            <artifactId>tuscany-host-embedded</artifactId>
+            <version>1.5-SNAPSHOT</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.tuscany.sca</groupId>
+            <artifactId>tuscany-implementation-java-runtime</artifactId>
+            <version>1.5-SNAPSHOT</version>
+            <scope>runtime</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.tuscany.sca</groupId>
+            <artifactId>tuscany-binding-ws-axis2</artifactId>
+            <version>1.5-SNAPSHOT</version>
+            <scope>runtime</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.tuscany.sca</groupId>
+            <artifactId>tuscany-host-tomcat</artifactId>
+            <version>1.5-SNAPSHOT</version>
+            <scope>runtime</scope>
+        </dependency>      
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.5</version>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-bundle-plugin</artifactId>
+
+                <configuration>
+                    <instructions>
+                        <Bundle-Version>${tuscany.version}</Bundle-Version>
+                        <Bundle-SymbolicName>org.apache.tuscany.sca.guardian</Bundle-SymbolicName>
+                        <Bundle-Description>${pom.name}</Bundle-Description>
+                        <Export-Package>org.apache.tuscany.sca.guardian*</Export-Package>
+                    </instructions>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/BlockingInterface.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/BlockingInterface.java
new file mode 100644
index 0000000000..848c4a874d
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/BlockingInterface.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.guardian;
+
+public interface BlockingInterface {
+
+    //@OneWay
+    public void block();
+
+    //@OneWay
+    public void unblock();
+
+    public boolean isBlocked();
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/Context.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/Context.java
new file mode 100644
index 0000000000..1b3cd72ead
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/Context.java
@@ -0,0 +1,74 @@
+/*
+ * 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.guardian;
+
+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");
+    private String name;
+    private List<GlobalException> exceptionList;
+
+    public Context(String name) {
+        this.name = name;
+        this.exceptionList = new LinkedList<GlobalException>();
+    }
+
+    public Context(String name, List exceptionList) {
+        this.name = name;
+        this.exceptionList = exceptionList;
+    }
+
+    public void addException(GlobalException ex) {
+        this.exceptionList.add(ex);
+    }
+
+    public void setExceptionList(List exceptionList) {
+        this.exceptionList = exceptionList;
+    }
+
+    public List 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/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GlobalException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GlobalException.java
new file mode 100644
index 0000000000..c500a32701
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GlobalException.java
@@ -0,0 +1,87 @@
+/*
+ * 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.guardian;
+
+public class GlobalException extends RuntimeException {
+
+    private Context signalingContext;
+    private Context targetContext; //Assigned by the recovery rules
+    private String signalingParticipant;
+
+    public GlobalException() {
+        super();
+    }
+
+    public GlobalException(String message) {
+        super(message);
+    }
+
+    public GlobalException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public GlobalException(Throwable cause) {
+        super(cause);
+    }
+
+    private void init() {
+    }
+
+    /**
+     * @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;
+    }
+
+    /**
+     * @return the signalingProcess
+     */
+    public String getSignalingParticipant() {
+        return signalingParticipant;
+    }
+
+    /**
+     * @param signalingProcess the signalingProcess to set
+     */
+    public void setSignalingParticipant(String signalingProcess) {
+        this.signalingParticipant = signalingProcess;
+    }
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianGroup.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianGroup.java
new file mode 100644
index 0000000000..12d7cf478b
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianGroup.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.guardian;
+
+public interface GuardianGroup extends GuardianPrimitives {
+
+    public void addGuardianMember(GuardianMember guardianMember);
+
+    public boolean removeGuardianMember(GuardianMember guardianMember);
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianGroupImpl.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianGroupImpl.java
new file mode 100644
index 0000000000..ee78dadddf
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianGroupImpl.java
@@ -0,0 +1,180 @@
+/*
+ * 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.guardian;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.osoa.sca.annotations.Scope;
+import org.apache.tuscany.sca.guardian.exceptions.*;
+import org.osoa.sca.annotations.Service;
+
+@Service(GuardianGroup.class)
+@Scope("COMPOSITE")
+public class GuardianGroupImpl implements GuardianGroup {
+
+    List<GuardianMember> guardianMembers;
+
+    public GuardianGroupImpl() {
+        guardianMembers = new LinkedList<GuardianMember>();
+    }
+
+    public void addGuardianMember(GuardianMember guardianMember) {
+        guardianMembers.add(guardianMember);
+        guardianMember.setUniqueParticipantID(guardianMembers.size() - 1);
+    }
+
+    public void enableContext(Context context) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public void removeContext() {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public void gthrow(GlobalException ex, List<String> participantList) {
+
+        //1)Ivoked by a GuardianMember instance through the gthrow method
+        //2)Notify all participants about the exception (FIFO atomic broadcast model) - it will cause the suspension of all participants
+        //  2.1)Invoke the gthrow of the guardian members associated with the participants on participantList
+
+        //Sends a message representing the exception to the other guardian members
+        if (participantList == null) {
+            for (GuardianMember g : guardianMembers) {
+                if (!g.getParticipantIdentifier().equals(ex.getSignalingParticipant())) {
+                    //g.gthrow(ex, participantList);
+                    g.gthrow(null, null);
+                }
+            }
+        } else {
+            for (GuardianMember g : guardianMembers) {
+                if (participantList.contains(g.getCurrentContext())) {
+                    //g.gthrow(ex, participantList);
+                    g.gthrow(null, null);
+                }
+            }
+        }
+
+        //Check if the participants are blocked
+        List<Integer> flags = new ArrayList<Integer>(guardianMembers.size());
+        for (int i = 0; i < guardianMembers.size(); i++) {
+            if (guardianMembers.get(i).getService().isBlocked()) {
+                flags.add(i, 1);
+            } else {
+                flags.add(i, 0);
+            }
+        }
+
+        //Wait until all participants are blocked
+        while (flags.contains(0)) {
+            try {
+                Thread.sleep(5000);
+            } catch (InterruptedException ex1) {
+                Logger.getLogger(GuardianGroupImpl.class.getName()).log(Level.SEVERE, null, ex1);
+            }
+        }
+
+        //3)Once ALL required participants are SUSPENDED (suspended point), invoke the defined Recovery Rules
+        for (GuardianMember g : guardianMembers) {
+            g.addException(new SuspendException());
+        }
+        //  3.1) recovery_rules < signaled exceptions + context information of all participant > target context + exception to raise
+
+        //Simpleste Recovery Rule: broadcast the exception for all participants - FIXME: hardcoded
+//        for (GuardianMemberImpl g : guardianMembers) {
+//            ex.setTargetContext(Context.CURRENT_CONTEXT);
+//            g.addException(ex);
+//        }
+
+        //HARDCODED - SERVER-BACKUP EXAMPLE
+        //Rule 1
+        if (ex instanceof JoinException) {
+            if (guardianMembers.size() > 1) {
+
+                PrimaryExistsException primaryExists = new PrimaryExistsException();
+                primaryExists.setTargetContext(new Context("MAIN"));
+
+                BackupJoinedException backupJoined = new BackupJoinedException();
+                backupJoined.setTargetContext(new Context("PRIMARY"));
+
+                for (GuardianMember g : guardianMembers) {
+                    //let p = JoinException.signaler
+                    if (g.getParticipantIdentifier().equals(ex.getSignalingParticipant())) {
+                        g.addException(primaryExists);
+                        System.out.println("adding PrimaryExistsException to " + g.getParticipantIdentifier());
+                    } else {
+                        g.addException(backupJoined);
+                        System.out.println("adding BackupJoinedException to " + g.getParticipantIdentifier());
+                    }
+                }
+            }
+        } //Rule 2
+        else if (ex instanceof PrimaryFailedException) {
+
+            PrimaryFailedException primaryFailedInit = new PrimaryFailedException();
+            primaryFailedInit.setTargetContext(Context.INIT_CONTEXT);
+
+            PrimaryFailedException primaryFailedMain = new PrimaryFailedException();
+            primaryFailedMain.setTargetContext(new Context("MAIN"));
+
+            for (GuardianMember g : guardianMembers) {
+                if (g.getCurrentContext().getName().equals("PRIMARY")) {
+                    System.out.println("adding PrimaryFailedException to " + g.getParticipantIdentifier());
+                    g.addException(primaryFailedInit);
+                } else if (g.getCurrentContext().getName().equals("BACKUP")) {
+                    System.out.println("adding PrimaryFailedException to " + g.getParticipantIdentifier());
+                    g.addException(primaryFailedMain);
+                }
+            }
+        } //Rule 3
+        else if (ex instanceof BackupFailedException) {
+
+            BackupFailedException backupFailedPrimary = new BackupFailedException();
+            backupFailedPrimary.setTargetContext(new Context("PRIMARY"));
+
+            BackupFailedException backupFailedInit = new BackupFailedException();
+            backupFailedInit.setTargetContext(Context.INIT_CONTEXT);
+
+            for (GuardianMember g : guardianMembers) {
+                if (g.getCurrentContext().getName().equals("PRIMARY")) {
+                    System.out.println("adding BackupFailedException to " + g.getParticipantIdentifier());
+                    g.addException(backupFailedPrimary);
+                } else if (g.getCurrentContext().getName().equals("BACKUP")) {
+                    System.out.println("adding BackupFailedException to " + g.getParticipantIdentifier());
+                    g.addException(backupFailedInit);
+                }
+            }
+
+        }
+    }
+
+    public boolean propagate(GlobalException ex) {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public void checkExceptionStatus() {
+        throw new UnsupportedOperationException("Not supported yet.");
+    }
+
+    public boolean removeGuardianMember(GuardianMember guardianMember) {
+        return this.guardianMembers.remove(guardianMember);
+    }
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianMember.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianMember.java
new file mode 100644
index 0000000000..460a89ce2d
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianMember.java
@@ -0,0 +1,36 @@
+/*
+ * 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.guardian;
+
+public interface GuardianMember extends GuardianPrimitives {
+
+    public void addException(GlobalException ex);
+
+    public void setService(BlockingInterface service);
+
+    public void removeService();
+
+    public Context getCurrentContext();
+
+    public BlockingInterface getService();
+
+    public String getParticipantIdentifier();
+
+    public void setUniqueParticipantID(int id);
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianMemberImpl.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianMemberImpl.java
new file mode 100644
index 0000000000..5edecf4bcd
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianMemberImpl.java
@@ -0,0 +1,209 @@
+/*
+ * 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.guardian;
+
+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.osoa.sca.annotations.Init;
+import org.osoa.sca.annotations.Reference;
+import org.osoa.sca.annotations.Scope;
+import org.osoa.sca.annotations.Destroy;
+
+@Scope("COMPOSITE")
+public class GuardianMemberImpl implements GuardianMember {
+
+    private Stack<Context> contextList;
+    private BlockingInterface service;
+    private Queue<GlobalException> exceptionQueue;
+    @Reference(name = "guardian_group", required = true)
+    public GuardianGroup guardianGroup;
+    private int id;
+
+    public GuardianMemberImpl() {
+        contextList = new Stack<Context>();
+        exceptionQueue = new LinkedList<GlobalException>();
+    }
+
+    @Init
+    public void init() {
+        guardianGroup.addGuardianMember(this);
+    }
+
+    @Destroy
+    public void destroy() {
+        guardianGroup.removeGuardianMember(this);
+    }
+
+    public void addException(GlobalException ex) {
+        exceptionQueue.add(ex);
+    }
+
+    public void setService(BlockingInterface service) {
+        this.service = service;
+    }
+
+    public Context getCurrentContext() {
+        return contextList.peek();
+    }
+
+    public BlockingInterface getService() {
+        return service;
+    }
+
+    public void enableContext(Context context) {
+        //Update the context list with the related set of exceptions
+        contextList.push(context);
+
+        if (contextList.size() == 1) {
+            gthrow(new JoinException(), null);
+        }
+
+    }
+
+    public void removeContext() {
+        if (!contextList.isEmpty()) {
+            contextList.pop();
+        }
+    }
+
+    //Adapt to allow a regular expression
+    //If participantList is null then signal to ALL participants
+    public void gthrow(GlobalException ex, List<String> participantList) {
+        //1)Block the participant until raise an exception
+        if (!service.isBlocked()) {
+            service.block();
+
+            if (ex != null) {
+                //Set the exception's parameters
+                ex.setSignalingContext(getCurrentContext());
+                ex.setSignalingParticipant(getParticipantIdentifier());
+
+                guardianGroup.gthrow(ex, participantList);
+            }
+
+        //if (participantList == null || !participantList.contains(getParticipantIdentifier())) {
+//            if (getParticipantIdentifier().equals(ex.getSignalingParticipant())) {
+//                //2A)Call the gthrow of the GuardianGroup - communicate with other guardian members
+//                System.out.println("HERE AT " + getParticipantIdentifier());
+//                guardianGroup.gthrow(ex, participantList);
+//            }
+
+        }
+
+
+    //*Is here the best place to receive such kind of msg?
+    //
+    //2B)When receive exception_msg from GuardianGroup do
+    //   if participant is not suspended then suspend it
+    //      if participant supports interrupts then
+    //          interrupt it, add SuspendException in the exception_queue, and invoke checkExceptionStatus
+    //      else invoke checkExceptionStatus periodically
+    //
+    //4)Once ALL required participants are SUSPENDED (suspended point), invoke the defined Recovery Rules
+    //  4.1) recovery_rules < signaled exceptions + context_list of all participant > target context + exception to raise
+    //  4.2) raise the resolved exception in each participant -> it goes to the exception_queue
+
+    }
+
+    public boolean propagate(GlobalException ex) {
+        //1)Compares the current context with the exception's target context
+        return !getCurrentContext().equals(ex.getTargetContext());
+    }
+
+    public void checkExceptionStatus() throws GlobalException {
+        //1)Chek the exception queue
+        //  1.1) if exception_queue is empty then return
+        //       else if first element on the exception_queue is SuspendException then
+        //          the method blocks until the next exception is received. The method raises the first non-SuspendException in the queue
+
+        GlobalException exc;
+
+        if ((exc = exceptionQueue.peek()) == null) {
+            System.out.println(getParticipantIdentifier() + "#No exception on exception queue");
+            return;
+        } else {
+            while ((exc = exceptionQueue.peek()) instanceof SuspendException) {
+                try {
+                    Thread.sleep(5000);
+                } catch (InterruptedException ex) {
+                    Logger.getLogger(GuardianMemberImpl.class.getName()).log(Level.SEVERE, null, ex);
+                }
+                exceptionQueue.poll();
+            }
+
+            service.unblock();
+
+//            if (exc != null) {
+//                System.out.println("\n" + getParticipantIdentifier() + "#");
+//                System.out.println("Exc: " + exc);
+//                System.out.println("TargetContext: " + exc.getTargetContext().getName());
+//                System.out.println("Signaling Participant: " + exc.getSignalingParticipant());
+//                System.out.println("Current Context: " + getCurrentContext().getName());
+//                System.out.println("Equals: " + exc.getTargetContext().equals(getCurrentContext()) + "\n");
+//            }
+
+            //FIX-ME: ex.targetContext() matches the participant id -> could use regular expressions
+            //Eg. ex.targetContext(): Main and participant id: Init/Main/Backup -> should throw the exception
+            String[] contexts = getParticipantIdentifier().split("\\.");
+            if (exc != null) {
+                for (int i = contexts.length - 1; i > 0; i--) {
+                    if (exc.getTargetContext().equals(new Context(contexts[i]))) {
+                        System.out.println(getParticipantIdentifier() + "#Returning an exception");
+                        exceptionQueue.poll();
+                        throw exc;
+                    }
+                }
+            }
+
+//            if (exc != null && exc.getTargetContext().equals(getCurrentContext())) {
+//                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 id = new StringBuffer();
+        id.append(this.id + "." + Context.INIT_CONTEXT.getName());
+        for (int i = 0; i < contextList.size(); i++) {
+            id.append("." + contextList.get(i).getName());
+//            if (i + 1 != contextList.size()) {
+//                id.append(".");
+//            }
+        }
+        return id.toString();
+    }
+
+    public void setUniqueParticipantID(int id) {
+        this.id = id;
+    }
+
+    public void removeService() {
+        this.service = null;
+    }
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianPrimitives.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianPrimitives.java
new file mode 100644
index 0000000000..a7710f811e
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/GuardianPrimitives.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.guardian;
+
+import java.util.List;
+
+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(GlobalException ex, List<String> participantList);
+
+    public boolean propagate(GlobalException ex);
+
+    //Method to check pending global exceptions
+    public void checkExceptionStatus();
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/JoinException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/JoinException.java
new file mode 100644
index 0000000000..b14ebeac2b
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/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.guardian;
+
+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/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/LeaveException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/LeaveException.java
new file mode 100644
index 0000000000..04e892f4bd
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/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.guardian;
+
+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/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/SuspendException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/SuspendException.java
new file mode 100644
index 0000000000..b7ede6d530
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/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.guardian;
+
+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/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/UnhandledException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/UnhandledException.java
new file mode 100644
index 0000000000..81e3844280
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/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.guardian;
+
+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/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/BackupFailedException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/BackupFailedException.java
new file mode 100644
index 0000000000..c4b2dd7de5
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/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.guardian.exceptions;
+
+import org.apache.tuscany.sca.guardian.*;
+
+public class BackupFailedException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/BackupJoinedException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/BackupJoinedException.java
new file mode 100644
index 0000000000..1fffa14663
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/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.guardian.exceptions;
+
+import org.apache.tuscany.sca.guardian.GlobalException;
+
+public class BackupJoinedException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/PrimaryExistsException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/PrimaryExistsException.java
new file mode 100644
index 0000000000..6d358c281e
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/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.guardian.exceptions;
+
+import org.apache.tuscany.sca.guardian.GlobalException;
+
+public class PrimaryExistsException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/PrimaryFailedException.java b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/PrimaryFailedException.java
new file mode 100644
index 0000000000..7f6b73cd05
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/java/org/apache/tuscany/sca/guardian/exceptions/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.guardian.exceptions;
+
+import org.apache.tuscany.sca.guardian.*;
+
+public class PrimaryFailedException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/guardian-model/src/main/resources/server-backup.composite b/sandbox/dougsleite/guardian-model/src/main/resources/server-backup.composite
new file mode 100644
index 0000000000..e2e27937d6
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/main/resources/server-backup.composite
@@ -0,0 +1,51 @@
+<?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:t="http://tuscany.apache.org/xmlns/sca/1.0"
+		targetNamespace="http://serverbackup"
+		name="serverbackup">
+
+	<component name="Participant1">
+		<implementation.java class="org.apache.tuscany.sca.guardian.itests.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember1"/>
+		<reference name="node" target="Participant2"/>
+	</component>  
+
+	<component name="Participant2">
+		<implementation.java class="org.apache.tuscany.sca.guardian.itests.NodeImpl"/>	
+		<reference name="guardian_member" target="GuardianMember2"/>
+		<reference name="node" target="Participant1"/>
+	</component>  
+
+	<component name="GuardianMember1">
+		<implementation.java class="org.apache.tuscany.sca.guardian.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianGroup"/> 
+	</component> 
+
+	<component name="GuardianMember2">
+		<implementation.java class="org.apache.tuscany.sca.guardian.GuardianMemberImpl"/> 
+		<reference name="guardian_group" target="GuardianGroup"/> 
+	</component> 
+
+	<component name="GuardianGroup">
+		<implementation.java class="org.apache.tuscany.sca.guardian.GuardianGroupImpl"/>
+	</component> 
+
+</composite>
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/ApplyUpdateFailureException.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/ApplyUpdateFailureException.java
new file mode 100644
index 0000000000..a40667ff8d
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/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.guardian.itests;
+
+public class ApplyUpdateFailureException extends RuntimeException {
+}
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/GuardianLaunch.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/GuardianLaunch.java
new file mode 100644
index 0000000000..11ede178d0
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/GuardianLaunch.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.guardian.itests;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class GuardianLaunch {
+
+    public static void main(String... args) throws IOException {
+
+        SCADomain scaDomain = SCADomain.newInstance("guardiangroup.composite");
+        System.in.read();
+    }
+}
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Launch.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Launch.java
new file mode 100644
index 0000000000..bb4b41163f
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Launch.java
@@ -0,0 +1,50 @@
+/*
+ * 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.guardian.itests;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class Launch {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("server-backup.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/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Launch2.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Launch2.java
new file mode 100644
index 0000000000..7b9e3fc1de
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Launch2.java
@@ -0,0 +1,50 @@
+/*
+ * 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.guardian.itests;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class Launch2 {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("server-backup.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();
+    }
+}
+
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Node.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Node.java
new file mode 100644
index 0000000000..6557aa4732
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Node.java
@@ -0,0 +1,34 @@
+/*
+ * 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.guardian.itests;
+
+import org.apache.tuscany.sca.guardian.BlockingInterface;
+import org.osoa.sca.annotations.OneWay;
+
+public interface Node extends BlockingInterface {
+
+    @OneWay
+    public void execute();
+
+    public void sendUpdate(String s);
+
+    public void applyUpdate();
+
+    public boolean isExecuting();
+}
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/NodeImpl.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/NodeImpl.java
new file mode 100644
index 0000000000..86d2e9bbc6
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/NodeImpl.java
@@ -0,0 +1,277 @@
+/*
+ * 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.guardian.itests;
+
+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.guardian.Context;
+import org.apache.tuscany.sca.guardian.GlobalException;
+import org.apache.tuscany.sca.guardian.GuardianMember;
+import org.osoa.sca.annotations.Init;
+import org.osoa.sca.annotations.Reference;
+import org.osoa.sca.annotations.Scope;
+import org.apache.tuscany.sca.guardian.exceptions.BackupFailedException;
+import org.apache.tuscany.sca.guardian.exceptions.BackupJoinedException;
+import org.apache.tuscany.sca.guardian.exceptions.PrimaryExistsException;
+import org.apache.tuscany.sca.guardian.exceptions.PrimaryFailedException;
+import org.osoa.sca.annotations.Destroy;
+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 isBlocked;
+    private Context mainContext;
+    private Context primaryContext;
+    private Context backupContext;
+    private List<GlobalException> exListMain;
+    private List<GlobalException> exListPrimary;
+    private int role;
+    private boolean isExecuting;
+    private String pID;
+    private Queue<String> updates;
+    @Reference(name = "guardian_member", required = true)
+    public GuardianMember gm;
+    @Reference(name = "node", required = true)
+    public Node node;
+    private boolean forcePSFException;
+    private boolean forceAUFException;
+
+    public NodeImpl() {
+        exListMain = new LinkedList();
+        exListMain.add(new PrimaryFailedException());
+        exListMain.add(new PrimaryExistsException());
+
+        exListPrimary = new LinkedList();
+        exListPrimary.add(new BackupFailedException());
+        exListPrimary.add(new BackupJoinedException());
+        exListPrimary.add(new PrimaryServiceFailureException());
+
+        mainContext = new Context("MAIN", exListMain);
+        primaryContext = new Context("PRIMARY", exListPrimary);
+        backupContext = new Context("BACKUP", null);
+
+        updates = new LinkedList();
+
+        isBlocked = false;
+        isExecuting = false;
+
+        node = null;
+
+        forcePSFException = false;
+        forceAUFException = false;
+    }
+
+    @Init
+    public void init() {
+        gm.setService(this);
+        pID = gm.getParticipantIdentifier();
+    }
+
+    @Destroy
+    public void destroy() {
+        gm.removeService();
+    }
+
+    public boolean isExecuting() {
+        return isExecuting;
+    }
+
+    @OneWay
+    public void execute() {
+        isExecuting = true;
+        gm.enableContext(mainContext);
+        role = PRIMARY;
+
+        while (true) {
+            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");
+                System.out.println(pID + "#Needs propagation?: " + gm.propagate(ex));
+
+                if (gm.propagate(ex)) {
+                    throw ex;
+                }
+
+                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;
+                    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;
+                    ex.printStackTrace();
+                    return;
+                }
+            }
+        }
+    }
+
+    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 void primaryService() {
+        boolean backupAvailable = false;
+        int upcount = 1;
+
+        while (true) {
+
+            gm.enableContext(primaryContext);
+
+            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 && node.isExecuting()) {
+                    node.sendUpdate("Update " + upcount);
+                    upcount++;
+                } else {
+                    System.out.println(pID + "#No backup available to send updates!");
+                }
+                //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;
+            } catch (BackupJoinedException ex) {
+                System.out.println(pID + "# Exception captured!: BackupJoinedException");
+                backupAvailable = true;
+            } finally {
+                gm.removeContext();
+            }
+        }
+    }
+
+    private void backupService() {
+        while (true) {
+
+            gm.enableContext(backupContext);
+
+            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();
+            }
+        }
+    }
+
+    //FIXME - It is not working asynchronously
+    //@OneWay
+    public void block() {
+        System.out.println(pID + "#Participant blocked!");
+        isBlocked = true;
+
+//        while (isBlocked) {
+//            try {
+//                Thread.sleep(5000);
+//            } catch (InterruptedException ex) {
+//                Logger.getLogger(ComponentImpl.class.getName()).log(Level.SEVERE, null, ex);
+//            }
+//        }
+    }
+
+    public boolean isBlocked() {
+        return isBlocked;
+    }
+
+    //@OneWay
+    public void unblock() {
+        System.out.println(pID + "#Participant unblocked!");
+        isBlocked = false;
+    }
+
+    public void sendUpdate(String update) {
+        System.out.println(pID + "#Receiving updates from primary: " + update);
+        updates.offer(update);
+    }
+
+    public void applyUpdate() {
+        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/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Participant1Launch.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Participant1Launch.java
new file mode 100644
index 0000000000..a5c360701a
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Participant1Launch.java
@@ -0,0 +1,45 @@
+/*
+ * 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.guardian.itests;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.guardian.exceptions.PrimaryFailedException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class Participant1Launch {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("participant1.composite");
+
+        try {
+
+            System.out.println("Starting participat1...");
+            Node c = scaDomain.getService(Node.class, "Participant1");
+            c.execute();
+
+            System.in.read();
+
+        } catch (PrimaryFailedException ex) {
+            System.out.println("Init#Exception captured!: PrimaryFailedException");
+
+        } finally {
+            scaDomain.close();
+        }
+    }
+}
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Participant2Launch.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Participant2Launch.java
new file mode 100644
index 0000000000..3478e4e105
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/Participant2Launch.java
@@ -0,0 +1,45 @@
+/*
+ * 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.guardian.itests;
+
+import java.io.IOException;
+import org.apache.tuscany.sca.guardian.exceptions.PrimaryFailedException;
+import org.apache.tuscany.sca.host.embedded.SCADomain;
+
+public class Participant2Launch {
+
+    public static void main(String... args) throws IOException {
+        SCADomain scaDomain = SCADomain.newInstance("participant2.composite");
+
+        try {
+
+            System.out.println("Starting participant2...");
+            Node c2 = scaDomain.getService(Node.class, "Participant2");
+            c2.execute();
+
+            System.in.read();
+
+        } catch (PrimaryFailedException ex) {
+            System.out.println("Init#Exception captured!: PrimaryFailedException");
+
+        } finally {
+            scaDomain.close();
+        }
+    }
+}
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/PrimaryServiceFailureException.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/PrimaryServiceFailureException.java
new file mode 100644
index 0000000000..3e8f6af7a6
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/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.guardian.itests;
+
+import org.apache.tuscany.sca.guardian.GlobalException;
+
+public class PrimaryServiceFailureException extends GlobalException {
+}
diff --git a/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/TestInterface.java b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/TestInterface.java
new file mode 100644
index 0000000000..5368de138f
--- /dev/null
+++ b/sandbox/dougsleite/guardian-model/src/test/java/org/apache/tuscany/sca/guardian/itests/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.guardian.itests;
+
+public interface TestInterface {
+
+    public void forcePrimaryServiceFailureException();
+
+    public void forceApplyUpdateFailureException();
+}