[Labs-l] slow queries

[Sean Pringle]

Hi!

Sometimes on labsdb we see slow queries. Some are marked with /* SLOW_OK */
comment, some are not.

Slow read queries are fine. InnoDB purge lag will climb but no big deal.

Slow write queries can make replication lag or block. Problem transactions
holding locks for days may get killed, regardless of SLOW_OK comments, to
maintain QoS.

If writing data on labsdbs try to do it in batches. It will make replag
rare, and in the event something does get killed, easier to resume.

BR
Sean
-- 
DBA @ WMF
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