Re: Postgres Replaying WAL slowly

[Jeff Frost <jeff@xxxxxxxxxxxxx>]

On Jun 30, 2014, at 12:17 PM, Jeff Frost <jeff@xxxxxxxxxxxxx> 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.