| Bug #70423 | performance_schema.replication_execute_status_by_worker wrong thread ID | ||
|---|---|---|---|
| Submitted: | 25 Sep 2013 20:38 | Modified: | 24 Oct 2013 13:01 |
| Reporter: | Marcelo Altmann (OCA) | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Replication | Severity: | S3 (Non-critical) |
| Version: | 5.7.2 | OS: | Linux |
| Assigned to: | CPU Architecture: | Any | |
[27 Sep 2013 8:33]
MySQL Verification Team
Hello Marcelo, Thank you for the bug report. Verified as described. Thanks, Umesh
[27 Sep 2013 20:49]
Shivji Jha
What this bug report states is not a bug in the multi-source replication labs release but a bug in MySQL 5.7.2 itself. Note that what Multi source replication labs release now shows is the intended behaviour. Some background: =============== information_schema.Id is the *connection* identifier. performance_schema's thread_id is a unique thread identifier (including *both background and foreground threads*), see http://dev.mysql.com/doc/refman/5.7/en/threads-table.html Both I_S and P_S maintain their own counters which they increment with every new thread/connection and hence the two may differ for say, IO/SQL/worker threads. About the bug: ============= In 5.7.2 the replication P_S tables show in thread_id column what I_S.processlist shows in the Id field. This is identified as a bug and we have corrected it in Multi source replication labs release, but not in 5.7 yet. After this bug fix, we will have the following situation: 1) Thread_id column in replication P_S tables show what other P_S tables do. 2) Thread_id column in replication P_S tables may NOT match I_S.processlist.Id 3) The mapping between I_S.processlist.Id and P_S.thread_id can be seen in the table P_S.threads
[24 Oct 2013 13:01]
Jon Stephens
Fixed in 5.7, documented as follows in the 5.7.3 changelog:
The THREAD_ID column values shown in the
PERFORMANCE_SCHEMA.REPLICATION_EXECUTE_STATUS_BY_WORKER table
used the same thread IDs shown in the output from SHOW
PROCESSLIST, rather than those used by other PERFORMANCE_SCHEMA
tables.
Closed.
Description: When showing replication status from performance_schema.replication_execute_status_by_worker it shows a thread ID that differ from SHOW PROCESSLIST How to repeat: mysql> select * from performance_schema.replication_execute_status_by_worker\G *************************** 1. row *************************** CHANNEL_NAME: CHANNEL1 WORKER_ID: 0 THREAD_ID: 30 SERVICE_STATE: ON LAST_SEEN_TRANSACTION: LAST_ERROR_NUMBER: 0 LAST_ERROR_MESSAGE: LAST_ERROR_TIMESTAMP: 0000-00-00 00:00:00 *************************** 2. row *************************** CHANNEL_NAME: CHANNEL1 WORKER_ID: 1 THREAD_ID: 31 SERVICE_STATE: ON LAST_SEEN_TRANSACTION: LAST_ERROR_NUMBER: 0 LAST_ERROR_MESSAGE: LAST_ERROR_TIMESTAMP: 0000-00-00 00:00:00 *************************** 3. row *************************** CHANNEL_NAME: CHANNEL2 WORKER_ID: 0 THREAD_ID: 34 SERVICE_STATE: ON LAST_SEEN_TRANSACTION: LAST_ERROR_NUMBER: 0 LAST_ERROR_MESSAGE: LAST_ERROR_TIMESTAMP: 0000-00-00 00:00:00 *************************** 4. row *************************** CHANNEL_NAME: CHANNEL2 WORKER_ID: 1 THREAD_ID: 35 SERVICE_STATE: ON LAST_SEEN_TRANSACTION: LAST_ERROR_NUMBER: 0 LAST_ERROR_MESSAGE: LAST_ERROR_TIMESTAMP: 0000-00-00 00:00:00 4 rows in set (0.00 sec) mysql> show processlist; +----+-------------+-----------+--------------------+---------+------+-----------------------------------------------------------------------------+------------------+ | Id | User | Host | db | Command | Time | State | Info | +----+-------------+-----------+--------------------+---------+------+-----------------------------------------------------------------------------+------------------+ | 8 | root | localhost | performance_schema | Sleep | 572 | | NULL | | 9 | system user | | NULL | Connect | 592 | Waiting for master to send event | NULL | | 10 | system user | | NULL | Connect | 592 | Slave has read all relay log; waiting for the slave I/O thread to update it | NULL | | 11 | system user | | NULL | Connect | 592 | Waiting for an event from Coordinator | NULL | | 12 | system user | | NULL | Connect | 592 | Waiting for an event from Coordinator | NULL | | 13 | system user | | NULL | Connect | 592 | Waiting for master to send event | NULL | | 14 | system user | | NULL | Connect | 591 | Slave has read all relay log; waiting for the slave I/O thread to update it | NULL | | 15 | system user | | NULL | Connect | 592 | Waiting for an event from Coordinator | NULL | | 16 | system user | | NULL | Connect | 592 | Waiting for an event from Coordinator | NULL | | 17 | root | localhost | performance_schema | Query | 0 | init | show processlist | +----+-------------+-----------+--------------------+---------+------+-----------------------------------------------------------------------------+------------------+ 10 rows in set (0.00 sec) Suggested fix: display the right thread ID