Re: High CPU usage / load average after upgrading to Ubuntu 12.04

Just to be clear - I was describing the current situation in our production.

We were running pgbench on different Ununtu versions today. I don’t have 12.04 setup at the moment, but I do have 12.10, which seems to be performing about the same as 12.04 in our tests with pgbench.
Running pgbench with 8 jobs and 32 clients resulted in load average of about 15 and TPS was 51350.

Question - how many cores does your server have? Ours has 8 cores.

Thanks,
Dan

-----Original Message-----
From: pgsql-performance-owner(at)postgresql(dot)org [mailto:pgsql-performance-owner(at)postgresql(dot)org] On Behalf Of Josh Berkus
Sent: Wednesday, February 13, 2013 7:26 PM
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] High CPU usage / load average after upgrading to Ubuntu 12.04

On 02/13/2013 11:24 AM, Josh Berkus wrote:
> On 02/12/2013 05:28 PM, Dan Kogan wrote:
>> Hi Will,
>>
>> Yes, I think we've seen some discussions on that. Our servers our hosted on Amazon Ec2 and upgrading the kernel does not seem so straight forward.
>> We did a benchmark using pgbench on 3.5 vs 3.2 and saw an improvement. Unfortunately our production server would not boot off 3.5 so we had to revert back to 3.2.
>>
>> At this point we are contemplating whether it's better to go back to 11.04 or upgrade to 12.10 (which comes with kernel version 3.5).
>> Any thoughts on that would be appreciated.
>
> I have a machine running the same version of Ubuntu. I'll run some
> tests and tell you what I find.

So I'm running a pgbench. However, I don't really have anything to compare the stats I'm seeing. CPU usage and load average was high (load 7.9), but that was on -j 8 -c 32, with a TPS of 8500.

What numbers are you seeing, exactly?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

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