Details
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Bug
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Status: Open (View Workflow)
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Major
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Resolution: Unresolved
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10.0.36, 10.1.36, 10.2.17
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None
Description
SHOW ENGINE INNODB STATUS uses different formats to print thread IDs in different sections of the output.
For example, the thread IDs are in decimal in the SEMAPHORES section:
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SEMAPHORES
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OS WAIT ARRAY INFO: reservation count 518859705
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--Thread 140189784869632 has waited at lock0lock.cc line 5636 for 0.0000 seconds the semaphore:
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Mutex at 0x7f8859c88068 '&lock_sys->mutex', lock var 1
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Last time reserved by thread 139857189899008 in file not yet reserved line 0, waiters flag 0
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wait has ended
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We can see that this semaphore is held by a thread with ID 139857189899008. To find that thread in the TRANSACTIONS section, we have to convert it to hex. This value in hex is 7F330A1F8B00. This conversion allows us to find the relevant transaction:
---TRANSACTION 2284134567, ACTIVE 724 sec unlock_row
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mysql tables in use 2, locked 1
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2649 lock struct(s), heap size 407080, 1 row lock(s)
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MySQL thread id 207695, OS thread handle 0x7f330a1f8b00, query id 41767441 10.1.1.31 appuser Sending data
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UPDATE ...
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The main thread ID is also in decimal:
Main thread process no. 13593, id 140188351182592, state: sleeping
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It might be worthwhile to change the output to be more consistent, so that users don't have to do decimal to hex conversions, and vice-versa. If not, then we should at least document this inconsistency.
https://mariadb.com/kb/en/library/show-engine-innodb-status/
Attachments
Issue Links
- relates to
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MDEV-18391 Print ENGINE INNODB STATUS in machine parsable format
- Open
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MDEV-18572 Thread executing DROP TABLE listed twice in SHOW ENGINE INNODB STATUS output
- Open
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MDEV-18698 Show InnoDB's internal background threads in SHOW ENGINE INNODB STATUS
- Open
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MDEV-21566 Lock monitor doesn't print a name for RW-latches
- Closed
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MDEV-22087 Increase buffer size for query in SHOW ENGINE INNODB STATUS output
- Open
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MDEV-17238 Document special thread IDs used in SHOW ENGINE INNODB STATUS output
- Open
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MDEV-18429 Consistent non-locking reads do not appear in TRANSACTIONS section of SHOW ENGINE INNODB STATUS
- Closed
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MDEV-18582 Port status variables related to SHOW ENGINE INNODB STATUS from XtraDB to InnoDB in 10.2+
- Closed
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MDEV-21330 Lock monitor doesn't print a semaphore's last reserved thread in non-debug builds and INFORMATION_SCHEMA.INNODB_SYS_SEMAPHORE_WAITS is totally broken
- Closed
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MDEV-21390 lock_print_info_summary() should work even when trx_sys.mutex is locked
- Closed