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MDEV-7399: Add support for INFORMATION_SCHEMA.INNODB_MUTEXES
MDEV-7618: Improve semaphore instrumentation
Introduced two new information schema tables to monitor mutex waits
and semaphore waits. Added a new configuration variable
innodb_intrument_semaphores to add thread_id, file name and
line of current holder of mutex/rw_lock.
27 lines
882 B
Plaintext
27 lines
882 B
Plaintext
# Establish connection con1 (user=root)
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# Establish connection con2 (user=root)
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drop table if exists t1;
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# Switch to connection con1
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create table t1 (id integer, x integer) engine = InnoDB;
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insert into t1 values(0, 0);
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set DEBUG_DBUG='+d,fatal-semaphore-timeout';
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set autocommit=0;
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# Sending query on con1,
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# the session will hold lock table mutex and sleep
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SELECT * from t1 where id = 0 FOR UPDATE;
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# Switch to connection con2
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set autocommit=0;
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# Sending query on con2,
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# the session will be blocked on the lock table mutex and
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# thus be put into sync arry
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SELECT * from t1 where id = 0 FOR UPDATE;
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# Switched to the default connection
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# Waitting for mysqld to crash
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# Mysqld crash was detected
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# Waitting for reconnect after mysqld restarts
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# Reconnected after mysqld was successfully restarted
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# Cleaning up before exit
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set DEBUG_DBUG=NULL;
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drop table if exists t1;
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# Clean exit
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