Re: Autovacuum running out of memory - Mailing list pgsql-performance

From Tom Lane
Subject Re: Autovacuum running out of memory
Date
Msg-id 15771.1313002463@sss.pgh.pa.us
Whole thread Raw
In response to Re: Autovacuum running out of memory  (Alexis Lê-Quôc <alq@datadoghq.com>)
Responses Re: Autovacuum running out of memory
List pgsql-performance
=?UTF-8?B?QWxleGlzIEzDqi1RdcO0Yw==?= <alq@datadoghq.com> writes:
> On Wed, Aug 10, 2011 at 1:17 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> However, I find it a bit odd that you're getting this failure in what
>> appears to be a 64-bit build.  That means you're not running out of
>> address space, so you must actually be out of RAM+swap.  Does the
>> machine have only 4GB or so of RAM?  If so, that value for
>> shared_buffers is unrealistically large; it's not leaving enough RAM for
>> other purposes such as this.

> The box has little under 8GB (it's on EC2, a "m1.large" instance)
> There is no swap.

Hmph.  Is there other stuff being run on the same instance?  Are there a
whole lot of active PG processes?  Maybe Amazon isn't really giving you
a whole 8GB, or there are weird address space restrictions in the EC2
environment.  Anyway I think I'd suggest reducing shared_buffers to 1GB
or so.

>> Where did you get the above-quoted parameter settings, anyway?

> In turn they come from High-Performance Postgresql 9.0
> (http://www.postgresql.org/about/news.1249)

I'm sure even Greg wouldn't claim his methods are good to more than one
or two significant digits.

            regards, tom lane

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