Re: Server slowing down over time

From: Jim Nasby <Jim(dot)Nasby(at)BlueTreble(dot)com>
To: Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Server slowing down over time
Date: 2015-09-14 22:08:07
Message-ID: 55F74547.40505@BlueTreble.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

On 9/4/15 6:59 AM, Tomas Vondra wrote:
>> Finally, whatever causes the database to wait also causes the
>> Windows instance to slow down. But restarting Postgresql fixes
>> this as well.
>
> That's a bit strange, I guess. If you're not observing light CPU and I/O
> usage, then the instance should not be slow, unless there's something
> else going on - possibly at the virtualization level (e.g. another busy
> instance on the same hardware, some sort of accounting that limits the
> resources after a time, etc.)

I've experienced something similar on linux before. Database is slow,
but neither CPU or IO is maxed. IIRC there was nothing disturbing in
pg_locks either. I don't recall the server actually slowing down, but
this would have been on something with at least 24 cores, so...

My suspicion has always been that there's some form of locking that
isn't being caught by the tools.
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Ben Chobot 2015-09-15 23:52:10 Re: VACUUM VERBOSE ANALYZE taking long time to process.
Previous Message Reza Taheri 2015-09-10 18:59:11 Announcing the public availability of the TPCx-V prototype