mariadb/mysql-test/t/kill.test
Davi Arnaut 2881b8014c Bug#37780: Make KILL reliable (main.kill fails randomly)
- A prerequisite cleanup patch for making KILL reliable.

The test case main.kill did not work reliably.

The following problems have been identified:

1. A kill signal could go lost if it came in, short before a
thread went reading on the client connection.

2. A kill signal could go lost if it came in, short before a
thread went waiting on a condition variable.

These problems have been solved as follows. Please see also
added code comments for more details.

1. There is no safe way to detect, when a thread enters the
blocking state of a read(2) or recv(2) system call, where it
can be interrupted by a signal. Hence it is not possible to
wait for the right moment to send a kill signal. It has been
decided, not to fix it in the code.  Instead, the test case
repeats the KILL statement until the connection terminates.

2. Before waiting on a condition variable, we register it
together with a synchronizating mutex in THD::mysys_var. After
this, we need to test THD::killed again. At some places we did
only test it in a loop condition before the registration. When
THD::killed had been set between this test and the registration,
we entered waiting without noticing the killed flag. Additional
checks ahve been introduced where required.

In addition to the above, a re-write of the main.kill test
case has been done. All sleeps have been replaced by Debug
Sync Facility synchronization. A couple of sync points have
been added to the server code.

To avoid further problems, if the test case fails in spite of
the fixes, the test case has been added to the "experimental"
list for now.

- Most of the work on this patch is authored by Ingo Struewing


mysql-test/t/kill.test:
  Re-wrote test case to use Debug Sync points instead of sleeps
sql/event_queue.cc:
  Fixed kill detection in Event_queue::cond_wait() by adding a check
  after enter_cond().
sql/lock.cc:
  Moved Debug Sync points behind enter_cond().
  Fixed comments.
sql/slave.cc:
  Fixed kill detection in start_slave_thread() by adding a check
  after enter_cond().
sql/sql_class.cc:
  Swapped order of kill and close in THD::awake().
  Added comments.
sql/sql_class.h:
  Added a comment to THD::killed.
sql/sql_parse.cc:
  Added a sync point in do_command().
sql/sql_select.cc:
  Added a sync point in JOIN::optimize().
2010-10-22 09:58:09 -02:00

601 lines
16 KiB
Text

#
# Test KILL and KILL QUERY statements.
#
# Killing a connection in an embedded server does not work like in a normal
# server, if it is waiting for a new statement. In an embedded server, the
# connection does not read() from a socket, but returns control to the
# application. 'mysqltest' does not handle the kill request.
#
-- source include/not_embedded.inc
-- source include/have_debug_sync.inc
--disable_warnings
SET DEBUG_SYNC = 'RESET';
DROP TABLE IF EXISTS t1, t2, t3;
DROP FUNCTION IF EXISTS MY_KILL;
--enable_warnings
delimiter |;
# Helper function used to repeatedly kill a session.
CREATE FUNCTION MY_KILL(tid INT) RETURNS INT
BEGIN
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION BEGIN END;
KILL tid;
RETURN (SELECT COUNT(*) = 0 FROM INFORMATION_SCHEMA.PROCESSLIST WHERE ID = tid);
END|
delimiter ;|
connect (con1, localhost, root,,);
connect (con2, localhost, root,,);
# Save id of con1
connection con1;
--disable_reconnect
let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
let $ignore= `SELECT @id := $ID`;
connection con1;
# Signal when this connection is terminating.
SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
# See if we can kill read().
# Run into read() immediately after hitting 'before_do_command_net_read'.
SET DEBUG_SYNC= 'before_do_command_net_read SIGNAL con1_read';
# Kill con1
connection con2;
SET DEBUG_SYNC='now WAIT_FOR con1_read';
# At this point we have no way to figure out, when con1 is blocked in
# reading from the socket. Sending KILL to early would not terminate
# con1. So we repeat KILL until con1 terminates.
let $wait_condition= SELECT MY_KILL(@id);
--source include/wait_condition.inc
# If KILL missed the read(), sync point wait will time out.
SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
SET DEBUG_SYNC = 'RESET';
connection con1;
--error 1053,2006,2013
SELECT 1;
--enable_reconnect
# this should work, and we should have a new connection_id()
SELECT 1;
let $ignore= `SELECT @id := $ID`;
SELECT @id != CONNECTION_ID();
#make sure the server is still alive
connection con2;
SELECT 4;
connection default;
--error ER_NOT_SUPPORTED_YET
KILL (SELECT COUNT(*) FROM mysql.user);
connection con1;
let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
let $ignore= `SELECT @id := $ID`;
connection con1;
disable_reconnect;
# Signal when this connection is terminating.
SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
# See if we can kill the sync point itself.
# Wait in 'before_do_command_net_read' until killed.
# It doesn't wait for a signal 'kill' but for to be killed.
# The signal name doesn't matter here.
SET DEBUG_SYNC= 'before_do_command_net_read SIGNAL con1_read WAIT_FOR kill';
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR con1_read';
# Repeat KILL until con1 terminates.
let $wait_condition= SELECT MY_KILL(@id);
--source include/wait_condition.inc
SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
SET DEBUG_SYNC = 'RESET';
connection con1;
--error 1053,2006,2013
SELECT 1;
enable_reconnect;
SELECT 1;
let $ignore= `SELECT @id := $ID`;
SELECT @id != CONNECTION_ID();
connection con2;
SELECT 4;
connection default;
#
# BUG#14851: killing long running subquery processed via a temporary table.
#
CREATE TABLE t1 (id INT PRIMARY KEY AUTO_INCREMENT);
CREATE TABLE t2 (id INT UNSIGNED NOT NULL);
INSERT INTO t1 VALUES
(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0),
(0),(0),(0),(0),(0),(0),(0),(0), (0),(0),(0),(0),(0),(0),(0),(0);
INSERT t1 SELECT 0 FROM t1 AS a1, t1 AS a2 LIMIT 4032;
INSERT INTO t2 SELECT id FROM t1;
connection con1;
let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
let $ignore= `SELECT @id := $ID`;
connection con1;
SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync';
# This is a very long running query. If this test start failing,
# it may be necessary to change to an even longer query.
send SELECT id FROM t1 WHERE id IN
(SELECT DISTINCT a.id FROM t2 a, t2 b, t2 c, t2 d
GROUP BY ACOS(1/a.id), b.id, c.id, d.id
HAVING a.id BETWEEN 10 AND 20);
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL @id;
SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
connection con1;
--error 1053,2006,2013
reap;
SELECT 1;
connection default;
SET DEBUG_SYNC = 'RESET';
DROP TABLE t1, t2;
#
# Test of blocking of sending ERROR after OK or EOF
#
connection con1;
let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
let $ignore= `SELECT @id := $ID`;
connection con1;
SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync WAIT_FOR kill';
send SELECT ACOS(0);
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
reap;
SELECT 1;
SELECT @id = CONNECTION_ID();
connection default;
SET DEBUG_SYNC = 'RESET';
#
# Bug#27563: Stored functions and triggers wasn't throwing an error when killed.
#
CREATE TABLE t1 (f1 INT);
delimiter |;
CREATE FUNCTION bug27563() RETURNS INT(11)
DETERMINISTIC
BEGIN
DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
RETURN 1;
END|
delimiter ;|
# Test stored functions
# Test INSERT
connection con1;
let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
let $ignore= `SELECT @id := $ID`;
connection con1;
send INSERT INTO t1 VALUES (bug27563());
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
--error 1317
reap;
SELECT * FROM t1;
connection default;
SET DEBUG_SYNC = 'RESET';
# Test UPDATE
INSERT INTO t1 VALUES(0);
connection con1;
send UPDATE t1 SET f1= bug27563();
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
--error 1317
reap;
SELECT * FROM t1;
connection default;
SET DEBUG_SYNC = 'RESET';
# Test DELETE
INSERT INTO t1 VALUES(1);
connection con1;
send DELETE FROM t1 WHERE bug27563() IS NULL;
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
--error 1317
reap;
SELECT * FROM t1;
connection default;
SET DEBUG_SYNC = 'RESET';
# Test SELECT
connection con1;
send SELECT * FROM t1 WHERE f1= bug27563();
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
--error 1317
reap;
SELECT * FROM t1;
connection default;
SET DEBUG_SYNC = 'RESET';
DROP FUNCTION bug27563;
# Test TRIGGERS
CREATE TABLE t2 (f2 INT);
delimiter |;
CREATE TRIGGER trg27563 BEFORE INSERT ON t1 FOR EACH ROW
BEGIN
DECLARE CONTINUE HANDLER FOR SQLSTATE '70100' SET @a:= 'killed';
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET @a:= 'exception';
INSERT INTO t2 VALUES(0);
SET DEBUG_SYNC= 'now SIGNAL in_sync WAIT_FOR kill';
INSERT INTO t2 VALUES(1);
END|
delimiter ;|
connection con1;
send INSERT INTO t1 VALUES(2),(3);
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
--error 1317
reap;
SELECT * FROM t1;
SELECT * FROM t2;
connection default;
SET DEBUG_SYNC = 'RESET';
DROP TABLE t1, t2;
#
# Bug#28598: mysqld crash when killing a long-running explain query.
#
connection con1;
let $ID= `SELECT @id := CONNECTION_ID()`;
connection con2;
let $ignore= `SELECT @id := $ID`;
connection con1;
--disable_query_log
let $tab_count= 40;
let $i= $tab_count;
while ($i)
{
eval CREATE TABLE t$i (a$i INT, KEY(a$i));
eval INSERT INTO t$i VALUES (1),(2),(3),(4),(5),(6),(7);
dec $i ;
}
SET SESSION optimizer_search_depth=0;
let $i=$tab_count;
while ($i)
{
let $a= a$i;
let $t= t$i;
dec $i;
if ($i)
{
let $comma=,;
let $from=$comma$t$from;
let $where=a$i=$a $and $where;
}
if (!$i)
{
let $from=FROM $t$from;
let $where=WHERE $where;
}
let $and=AND;
}
--enable_query_log
SET DEBUG_SYNC= 'before_join_optimize SIGNAL in_sync';
eval PREPARE stmt FROM 'EXPLAIN SELECT * $from $where';
send EXECUTE stmt;
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
KILL QUERY @id;
connection con1;
--error 1317
reap;
--disable_query_log
let $i= $tab_count;
while ($i)
{
eval DROP TABLE t$i;
dec $i ;
}
--enable_query_log
connection default;
SET DEBUG_SYNC = 'RESET';
--echo #
--echo # Bug#19723: kill of active connection yields different error code
--echo # depending on platform.
--echo #
--echo
--echo # Connection: con1.
--connection con1
let $ID= `SELECT @id := CONNECTION_ID()`;
SET DEBUG_SYNC= 'thread_end SIGNAL con1_end';
--disable_reconnect
--error ER_QUERY_INTERRUPTED
KILL @id;
connection con2;
SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
connection con1;
--echo # ER_SERVER_SHUTDOWN, CR_SERVER_GONE_ERROR, CR_SERVER_LOST,
--echo # depending on the timing of close of the connection socket
--error 1053,2006,2013
SELECT 1;
--enable_reconnect
SELECT 1;
let $ignore= `SELECT @id := $ID`;
SELECT @id != CONNECTION_ID();
connection default;
SET DEBUG_SYNC = 'RESET';
--echo #
--echo # Additional test for WL#3726 "DDL locking for all metadata objects"
--echo # Check that DDL and DML statements waiting for metadata locks can
--echo # be killed. Note that we don't cover all situations here since it
--echo # can be tricky to write test case for some of them (e.g. REPAIR or
--echo # ALTER and other statements under LOCK TABLES).
--echo #
--disable_warnings
drop tables if exists t1, t2, t3;
--enable_warnings
create table t1 (i int primary key);
connect (blocker, localhost, root, , );
connect (dml, localhost, root, , );
connect (ddl, localhost, root, , );
--echo # Test for RENAME TABLE
--echo # Switching to connection 'blocker'
connection blocker;
lock table t1 read;
--echo # Switching to connection 'ddl'
connection ddl;
let $ID= `select connection_id()`;
--send rename table t1 to t2
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "rename table t1 to t2";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Test for DROP TABLE
--send drop table t1
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "drop table t1";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Test for CREATE TRIGGER
--send create trigger t1_bi before insert on t1 for each row set @a:=1
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "create trigger t1_bi before insert on t1 for each row set @a:=1";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo #
--echo # Tests for various kinds of ALTER TABLE
--echo #
--echo # Full-blown ALTER which should copy table
--send alter table t1 add column j int
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "alter table t1 add column j int";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Two kinds of simple ALTER
--send alter table t1 rename to t2
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "alter table t1 rename to t2";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--send alter table t1 disable keys
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "alter table t1 disable keys";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Fast ALTER
--send alter table t1 alter column i set default 100
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "alter table t1 alter column i set default 100";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Special case which is triggered only for MERGE tables.
--echo # Switching to connection 'blocker'
connection blocker;
unlock tables;
create table t2 (i int primary key) engine=merge union=(t1);
lock tables t2 read;
--echo # Switching to connection 'ddl'
connection ddl;
--send alter table t2 alter column i set default 100
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "alter table t2 alter column i set default 100";
--source include/wait_condition.inc
--replace_result $ID ID
eval kill query $ID;
--echo # Switching to connection 'ddl'
connection ddl;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Test for DML waiting for meta-data lock
--echo # Switching to connection 'blocker'
connection blocker;
unlock tables;
lock tables t1 read;
--echo # Switching to connection 'ddl'
connection ddl;
# Let us add pending exclusive metadata lock on t2
--send truncate table t1
--echo # Switching to connection 'dml'
connection dml;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "truncate table t1";
--source include/wait_condition.inc
let $ID2= `select connection_id()`;
--send insert into t1 values (1)
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table metadata lock" and
info = "insert into t1 values (1)";
--source include/wait_condition.inc
--replace_result $ID2 ID2
eval kill query $ID2;
--echo # Switching to connection 'dml'
connection dml;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Switching to connection 'blocker'
connection blocker;
unlock tables;
--echo # Switching to connection 'ddl'
connection ddl;
--reap
--echo # Test for DML waiting for tables to be flushed
--echo # Switching to connection 'blocker'
connection blocker;
lock tables t1 read;
--echo # Switching to connection 'ddl'
connection ddl;
--echo # Let us mark locked table t1 as old
--send flush tables
--echo # Switching to connection 'dml'
connection dml;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table flush" and
info = "flush tables";
--source include/wait_condition.inc
--send select * from t1
--echo # Switching to connection 'default'
connection default;
let $wait_condition=
select count(*) = 1 from information_schema.processlist
where state = "Waiting for table flush" and
info = "select * from t1";
--source include/wait_condition.inc
--replace_result $ID2 ID2
eval kill query $ID2;
--echo # Switching to connection 'dml'
connection dml;
--error ER_QUERY_INTERRUPTED
--reap
--echo # Switching to connection 'blocker'
connection blocker;
unlock tables;
--echo # Switching to connection 'ddl'
connection ddl;
--reap
--echo # Cleanup.
--echo # Switching to connection 'default'
connection default;
drop table t1;
drop table t2;
###########################################################################
SET DEBUG_SYNC = 'RESET';
DROP FUNCTION MY_KILL;