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ed04c40b01
Delay spawning parallel replication worker threads until a slave SQL thread is running, and de-spawn them when the last SQL thread stops. This is especially useful to avoid needless threads on a master in a setup where same my.cnf is used on masters and slaves.
23 lines
1.1 KiB
Plaintext
23 lines
1.1 KiB
Plaintext
SET @save_slave_parallel_threads= @@GLOBAL.slave_parallel_threads;
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SELECT IF(COUNT(*) < 20, "OK", CONCAT("Found too many system user processes: ", COUNT(*))) FROM information_schema.processlist WHERE user = "system user";
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IF(COUNT(*) < 20, "OK", CONCAT("Found too many system user processes: ", COUNT(*)))
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OK
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SELECT @@GLOBAL.slave_parallel_threads as 'must be 20 because of .cnf';
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must be 20 because of .cnf
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20
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SELECT @@SESSION.slave_parallel_threads as 'no session var';
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ERROR HY000: Variable 'slave_parallel_threads' is a GLOBAL variable
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SET GLOBAL slave_parallel_threads= 0;
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SET GLOBAL slave_parallel_threads= DEFAULT;
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SELECT @@GLOBAL.slave_parallel_threads as 'must be 0 because of default';
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must be 0 because of default
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0
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SET GLOBAL slave_parallel_threads= 10;
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SELECT @@GLOBAL.slave_parallel_threads;
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@@GLOBAL.slave_parallel_threads
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10
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SELECT IF(COUNT(*) < 10, "OK", CONCAT("Found too many system user processes: ", COUNT(*))) FROM information_schema.processlist WHERE user = "system user";
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IF(COUNT(*) < 10, "OK", CONCAT("Found too many system user processes: ", COUNT(*)))
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OK
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SET GLOBAL slave_parallel_threads = @save_slave_parallel_threads;
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