Re: Ubuntu 12.04 / 3.2 Kernel Bad for PostgreSQL Performance

On Thu, Dec 6, 2012 at 1:28 AM, Shaun Thomas <sthomas(at)optionshouse(dot)com> wrote:

> This isn't a question, but a kind of summary over a ton of investigation
> I've been doing since a recent "upgrade". Anyone else out there with
> "big iron" might want to confirm this, but it seems pretty reproducible.
> This seems to affect the latest 3.2 mainline and by extension, any
> platform using it. My tests are restricted to Ubuntu 12.04, but it may
> apply elsewhere.

I'm not seeing this on our production systems. I haven't run benchmarks.

One of our systems currently has a mixture of PG 8.4 shards running on
Ubuntu 10.04 (2.6 kernel) and PG 9.1 shards running on Ubuntu 12.04
(3.2 kernel). Load & cpu utilization (per 'top') are comparable.
Shards have 64GB of RAM, shared_buffers=3GB, 60 active connections.

Another production PG 9.1 system with shared_buffers=5GB also seems
fine. Old load graphs show the load is comparable from when it was
running Ubuntu 10.04.

My big systems are still all on Ubuntu 10.04 (cut over in January I expect).

--
Stuart Bishop <stuart(at)stuartbishop(dot)net>
http://www.stuartbishop.net/