Re: pg_basebackup blocking all queries with horrible performance

On Thu, Jun 7, 2012 at 8:04 PM, Lonni J Friedman <netllama@gmail.com> wrote:
> On Thu, Jun 7, 2012 at 10:41 AM, Lonni J Friedman <netllama@gmail.com> wrote:
>> Greetings,
>> I have a 4 server postgresql-9.1.3 cluster (one master doing streaming
>> replication to 3 hot standby servers).  All of them are running
>> Fedora-16-x86_64.
>>
>> http://wiki.postgresql.org/wiki/Lock_Monitoring
>
> err, i included that URL but neglected to explain why.  On a different
> list someone suggested that I verify that there were no locks that
> were blocking things, and I did so, and found no locks.
>
> So I'm still at a loss why pg_basebackup is killing perf, and would
> appreciate pointers on how to debug it or at least reduce its impact
> on performance if that is possible.
>

My guess would be that you are overloading your I/O system. You should
look at values from iostat and vmstat from when the system works fine
and when you run pg_basebackup, that should give you a hint in the
right direction.

-- 
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/