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Re: MySQL is eating all the CPU 100% - Guide me to fix this please
Posted by: Peter Brawley
Date: October 22, 2017 12:37PM

Too many queries require table scans, they need to be optimised to use indexes. The slow query log can help identify them.

The system is doing 900k table seeks/sec, that's crazy. key_read_requests/key_reads and key_write_requests/key_writes are way too high. You need to cut that number way down by optimising queries. Key_buffer_size should be big enough at least to hold all MyISAM indexes.

The query cache is not helping. It's deprecated in 5.7, removed in 8.0. Disable it.

The system is creating 90 disk tmp tables/sec. That's too many. Grow tmp table size & max_heap_size, have queries use Heap tmp tables.

The system is opening 360 files/sec. Grow table_open_cache.

638 queries/sec is very busy, you may need better hardware.

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November 07, 2017 09:51AM
Re: MySQL is eating all the CPU 100% - Guide me to fix this please
October 22, 2017 12:37PM


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