Re: Postgres Replaying WAL slowly - Mailing list pgsql-performance

From Jeff Frost
Subject Re: Postgres Replaying WAL slowly
Date
Msg-id F3E1168D-8D49-407E-A8B7-B3ED81C93DCB@pgexperts.com
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In response to Re: Postgres Replaying WAL slowly  (Jeff Frost <jeff@pgexperts.com>)
Responses Re: Postgres Replaying WAL slowly
List pgsql-performance
On Jun 30, 2014, at 12:17 PM, Jeff Frost <jeff@pgexperts.com> wrote:


already is quite helpful.

What are you doing on that system? Is there anything requiring large
amounts of access exclusive locks on the primary? Possibly large amounts
of temporary relations?


The last time we did a 100% logging run, the peak temp table creation was something like 120k/hr, but the replicas seemed able to keep up with that just fine.


Sampling pg_locks on the primary shows ~50 locks with ExclusiveLock mode:

           mode           | count
--------------------------+-------
 AccessExclusiveLock      |    11
 AccessShareLock          |  2089
 ExclusiveLock            |    46
 RowExclusiveLock         |    81
 RowShareLock             |    17
 ShareLock                |     4
 ShareUpdateExclusiveLock |     5

Seems to be relatively consistent.  Of course, it's hard to say what it looked like back when the issue began.



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