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Long Semaphore Wait Due to Async Flush + InnoDB Monitor + buf0flu.c + buf0buf.c (Doc ID 1347842.1)

Last updated on SEPTEMBER 04, 2023

Applies to:

MySQL Server - Version 4.0 and later
Information in this document applies to any platform.


The MySQL error log contains warnings from InnoDB that there are long semaphore waits and the main thread is in the "flushing buffer pool pages" state. For the semaphores there will be messages about locks created in the files buf0buf.c and/or buf0fly.c

Here is a sample of the InnoDB Monitor Output from MySQL 5.0:


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