Turns out yesterday we fixed a bug and introduced a new bug, which was previously hidden by yet another bug which in turn we had fixed last week... %)
In result last fix led to greatly increased number of requests to the database.
But still, thanks for that, we found out about too frequent checkpoints and that our recommendations table has three times more dead tuples than live ones.
We will fix our autovacuum configuration.
As for other problem - 100% cpu load with idle disks - it is no more reproducing and we don't want it to :)
Thanks Ilya and Torsten!
Dmitriy Shalashov
2014-04-25 13:47 GMT+04:00 Torsten Förtsch <torsten.foertsch@xxxxxxx>:
On 25/04/14 09:47, Дмитрий Шалашов wrote:Maybe the table has reached the state where it needs a VACUUM FREEZE.
> Half a day ago one of our production PG servers (arguably busiest one)
> become very slow; I went to investigate the issue and found that it runs
> simultaneously '(auto)VACUUM ANALYZE recommendations' - largest table on
> that server - and checkpoint, giving a 100% disk load
Autovacuum does that for you but it requires a complete scan of the table.
Torsten
