Details
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Task
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Status: Closed (View Workflow)
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Major
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Resolution: Duplicate
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None
Description
Currently number of purge threads is static variable and require server shutdown and restart to be able to change. This should be changed to dynamic variable.
Attachments
Issue Links
- duplicates
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MDEV-26520 Make innodb_purge_threads settable without server restart
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- Closed
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- relates to
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MDEV-11802 innodb.innodb_bug14676111 fails in buildbot due to InnoDB purge failing to start when there is work to do
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- Closed
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I think that instead of doing this, we should benchmark and evaluate the current architecture. Could the interplay between the purge coordinator and worker threads be improved? A simpler architecture could as a side effect fix
MDEV-11802.For a benchmark, I would suggest something like the following:
-- run a well defined load of INSERT, UPDATE, DELETE (no ROLLBACK) in other connections
-- then, repeat the following until History list length reaches 0, and measure the time
SHOW ENGINE INNODB STATUS;
During the last phase it would also be beneficial to run perf record or similar, to see where the time is being spent. It would also be useful to monitor the CPU usage with top or similar, to see if purge is actually running as fast as possible on an otherwise idle system, until there is no work to do.