Re: Very slow DELETE, UPDATE, INSERT on a new server

[Rick James]

For a 32GB system, you could increase this significantly:
innodb buffer pool size 134,217,728
(unless you really don't have much data in InnoDB tables)

SHOW CREATE TABLE module_userprefs \G -- engine, etc
SHOW TABLE STATUS LIKE 'module_userprefs' \G -- size, etc

The two slowlog entries happened at the same time and overlapped completely. Was there anything else overlapping them?

query cache type ON
Consider turning it OFF or DEMAND.
SHOW STATUS LIKE 'Qcache_%';


8 cores -- Turn off 4. Interlocks on Query Cache, key_buffer, and malloc in InnoDB are all inefficiently implemented. 8 cores sometimes runs slower than 4.

During the "hang", what did SHOW PROCESSLIST show?

Sorry, none of the above are likely to answer your question.