Re: Sudden Query slowdown on our Postgresql Server

What does vmstat say about things like context switches / interrupts per second?

On Thu, Mar 22, 2012 at 10:53 PM, Sebastian Melchior <webmaster@mailz.de> wrote:
> Hi,
>
> we already used iostat and iotop during times of the slowdown, there is no sudden drop in I/O workload in the times
ofthe slowdown. Also the iowait does not spike and stays as before. 
> So i do not think that this is I/O related. As the disks are SSDs there also still is some "head room" left.
>
> Sebastian
>
> On 23.03.2012, at 05:48, Scott Marlowe wrote:
>
>> I'd suggest the handy troubleshooting tools sar, iostat, vmstat and iotop
>>
>> On Thu, Mar 22, 2012 at 10:37 PM, Sebastian Melchior <webmaster@mailz.de> wrote:
>>> Hi,
>>>
>>> yeah we log those, those times do not match the times of the slowdown at all. Seems to be unrelated.
>>>
>>> Sebastian
>>>
>>>
>>> On 23.03.2012, at 01:47, Stephen Frost wrote:
>>>
>>>> * Sebastian Melchior (webmaster@mailz.de) wrote:
>>>>> Does anyone have any idea what could cause this issue or how we can further debug it?
>>>>
>>>> Are you logging checkpoints?  If not, you should, if so, then see if
>>>> they correllate to the time of the slowdown..?
>>>>
>>>>       Thanks,
>>>>
>>>>               Stephen
>>>
>>>
>>> --
>>> Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
>>> To make changes to your subscription:
>>> http://www.postgresql.org/mailpref/pgsql-performance
>>
>>
>>
>> --
>> To understand recursion, one must first understand recursion.
>



--
To understand recursion, one must first understand recursion.