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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5.5.36, 10.0.9
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None
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None
Description
Using mariadb-10.0.9-linux-x86_64.tar.gz.
MariaDB [test]> show global status like 'com_insert';
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+---------------+--------+
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| Variable_name | Value |
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+---------------+--------+
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| Com_insert | 646298 |
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+---------------+--------+
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1 row in set (0.00 sec)
|
|
|
MariaDB [test]> stop slave;
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Query OK, 0 rows affected (0.00 sec)
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|
|
MariaDB [test]> show global status like 'com_insert';
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+---------------+-------+
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| Variable_name | Value |
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+---------------+-------+
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| Com_insert | 0 |
|
+---------------+-------+
|
1 row in set (0.00 sec)
|
Attachments
Activity
| Field | Original Value | New Value |
|---|---|---|
| Description |
Using mariadb-10.0.9-linux-x86_64.tar.gz. MariaDB [test]> show global status like 'com_insert'; +---------------+--------+ | Variable_name | Value | +---------------+--------+ | Com_insert | 646298 | +---------------+--------+ 1 row in set (0.00 sec) MariaDB [test]> stop slave; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> show global status like 'com_insert'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Com_insert | 0 | +---------------+-------+ 1 row in set (0.00 sec) |
Using mariadb-10.0.9-linux-x86_64.tar.gz. {noformat} MariaDB [test]> show global status like 'com_insert'; +---------------+--------+ | Variable_name | Value | +---------------+--------+ | Com_insert | 646298 | +---------------+--------+ 1 row in set (0.00 sec) MariaDB [test]> stop slave; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> show global status like 'com_insert'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Com_insert | 0 | +---------------+-------+ 1 row in set (0.00 sec) {noformat} |
| Assignee | Elena Stepanova [ elenst ] |
| Fix Version/s | 10.0.10 [ 14500 ] | |
| Fix Version/s | 5.5.37 [ 15000 ] | |
| Affects Version/s | 5.5.36 [ 14600 ] | |
| Assignee | Elena Stepanova [ elenst ] | Michael Widenius [ monty ] |
| Priority | Blocker [ 1 ] | Critical [ 2 ] |
| Status | Open [ 1 ] | In Progress [ 3 ] |
Problem was that global status was not updated when slave thread thd was deleted.
Fix pushed into 5.5. Will be in 10.0.10 when we do next merge from 5.5
| Resolution | Fixed [ 1 ] | |
| Status | In Progress [ 3 ] | Closed [ 6 ] |
| Workflow | defaullt [ 36421 ] | MariaDB v2 [ 43404 ] |
| Workflow | MariaDB v2 [ 43404 ] | MariaDB v3 [ 62495 ] |
| Comment |
[ The original buildbot test failure can be reproduced easily by injecting the following sleep in the code: {noformat} diff --git a/sql/slave.cc b/sql/slave.cc index 4129c4c..32e6bd4 100644 --- a/sql/slave.cc +++ b/sql/slave.cc @@ -4837,6 +4837,7 @@ log '%s' at position %s, relay log '%s' position: %s%s", RPL_LOG_NAME, mysql_cond_broadcast(&rli->stop_cond); DBUG_EXECUTE_IF("simulate_slave_delay_at_terminate_bug38694", sleep(5);); mysql_mutex_unlock(&rli->run_lock); // tell the world we are done +my_sleep(500000); /* Deactivate the parallel replication thread pool, if there are now no more {noformat} ] |
| Workflow | MariaDB v3 [ 62495 ] | MariaDB v4 [ 147613 ] |
The problem was introduced in 5.5 tree by the following revision:
revno: 3601revision-id: wlad@montyprogram.com-20121220231237-0xv7egt3s225bx7jparent: timour@askmonty.org-20121220203840-ofoavsm70g8ouk0mcommitter: Vladislav Vaintroub <wlad@montyprogram.com>branch nick: 5.5timestamp: Fri 2012-12-21 00:12:37 +0100message:MDEV-3945 - do not hold LOCK_thread_count when freeing THD.The patch decreases the duration of LOCK_thread_count, so it is not hold during THD destructor and freeing memory.This mutex now only protects the integrity of threads list, when removing THD from it, and thread_count variable.The add_to_status() function that updates global status during client disconnect, is now correctly protected by the LOCK_status mutex.Benchmark : in a "non-persistent" sysbench test (oltp_ro with reconnect after each query), ~ 25% more connects/disconnects were measuredI agree that the effect is bad and must be fixed, but given that it had survived for over an year without affecting anybody heavily enough to be noticed, I demote it from Blocker