Details
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Bug
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Status: Closed (View Workflow)
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Critical
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Resolution: Fixed
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10.0(EOL), 10.1(EOL)
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None
Description
During server shutdown slave SQL thread broadcasts "stopped" too early:
mysql_cond_broadcast(&rli->stop_cond);
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DBUG_EXECUTE_IF("simulate_slave_delay_at_terminate_bug38694", sleep(5););
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mysql_mutex_unlock(&rli->run_lock); // tell the world we are done
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/*
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Deactivate the parallel replication thread pool, if there are now no more
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SQL threads running. Do this here, when we have released all locks, but
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while our THD (and current_thd) is still valid.
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*/
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mysql_mutex_lock(&LOCK_active_mi);
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if (opt_slave_parallel_threads > 0 &&
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!master_info_index->any_slave_sql_running())
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rpl_parallel_inactivate_pool(&global_rpl_thread_pool);
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mysql_mutex_unlock(&LOCK_active_mi);
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mysql_mutex_lock(&LOCK_thread_count);
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THD_CHECK_SENTRY(thd);
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delete thd;
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mysql_mutex_unlock(&LOCK_thread_count);
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This causes enormous number of sporadic replication test failures with crashes, hangs and warnings like "Plugin '...' has ref_count=1 after shutdown".
To reproduce this failure reliably, just add sleep(1) immediately after condition is signaled and run tests as usual:
diff --git a/sql/slave.cc b/sql/slave.cc
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index 4129c4c..efc75f3 100644
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--- a/sql/slave.cc
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+++ b/sql/slave.cc
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@@ -4837,6 +4837,7 @@ log '%s' at position %s, relay log '%s' position: %s%s", RPL_LOG_NAME,
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mysql_cond_broadcast(&rli->stop_cond);
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DBUG_EXECUTE_IF("simulate_slave_delay_at_terminate_bug38694", sleep(5););
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mysql_mutex_unlock(&rli->run_lock); // tell the world we are done
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+ sleep(1);
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/*
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Deactivate the parallel replication thread pool, if there are now no more
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This seem to be appeared after:
commit 682ed005c57dabb4615052a79789e44e5c93525c
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Author: Kristian Nielsen <knielsen@knielsen-hq.org>
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Date: Wed Jun 10 11:57:42 2015 +0200
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MDEV-8294: Inconsistent behavior of slave parallel threads at runtime
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There were some cases where the slave SQL thread could stop without
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the pool of parallel replication worker threads being correctly
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de-activated.
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Attachments
Issue Links
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- Closed
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