Details
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Bug
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Status: Closed (View Workflow)
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Critical
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Resolution: Incomplete
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10.3.27
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Debian 9.13
10.3.27-MariaDB
Description
The server is performing a heavy migration task and the task of recalculating data, parallel and in unrelated tables. Every 30 min we have problems with semaphores.
DML (update/delete/insert) queries accumulate in queue
In the attachment, a fragment of the log.
If you need something else we provide.
Attachments
Issue Links
- relates to
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MDEV-24294 MariaDB - Cluster freezes if node hangs
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- Closed
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MDEV-29809 MariaDB: node crash and recovery - Semaphore wait has lasted > 600 seconds. We intentionally crash....
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- Closed
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most of the threads are waiting to acquire dict_operation_lock. Remaining threads are waiting for index->lock. The below is the semaphore wait for the index lock:
Feb 28 16:11:57 - mysqld: --Thread 139955004458752 has waited at btr0cur.cc line 1357 for 573.00 seconds the semaphore:
Feb 28 16:11:57 - mysqld: SX-lock on RW-latch at 0x7f49c0010830 created in file dict0dict.cc line 2130
Feb 28 16:11:57 - mysqld: a writer (thread id 139955038029568) has reserved it in mode SX
Feb 28 16:11:57 - mysqld: number of readers 0, waiters flag 1, lock_word: 10000000
Feb 28 16:11:57 - mysqld: Last time write locked in file dict0stats.cc line 1969
I don't see any info about Thread 139955038029568 in the output.
can you attach gdb while hanging and get thr a a bt ?
producing stack trace (https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/) could help more in
understanding the root cause of the issue.