[pgpool-general: 1717] Re: poor performance w/ pgpool

Tatsuo Ishii ishii at postgresql.org
Sat May 11 09:41:18 JST 2013


Thanks for the report. I'm looking forward to hearing from you about
the results of additional testing.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp

> It looks like disabling SSL has helped performance.  I'm still running additional tests and I'll report back.
> 
> Thanks!
> ----- Original Message -----
> From: "Kyle O'Donnell" <kyleo at 0b10.mx>
> To: "Tatsuo Ishii" <ishii at postgresql.org>
> Cc: pgpool-general at pgpool.net
> Sent: Wednesday, May 8, 2013 7:40:12 PM
> Subject: [pgpool-general: 1705] Re: poor performance w/ pgpool
> 
> Thanks for the info.
> 
> There are 8 cores available per server and most of them are idle (only about 3 cores were active at ~30% CPU) so I don't think that's an issue.
> 
> We are using all 10GB network and not generating near that amount of traffic (~40mb/sec at peak)
> 
> The disks are all SAN (stripped across 2x5disk raid5s with 4GB of write cache) and there is less than 1ms io wait on average.
> 
> SSL is enabled.  I'll try to disable that and let you know the results.
> 
> -Kyle
> 
> ----- Original Message -----
> From: "Tatsuo Ishii" <ishii at postgresql.org>
> To: kyleo at 0b10.mx
> Cc: pgpool-general at pgpool.net
> Sent: Wednesday, May 8, 2013 7:10:37 PM
> Subject: Re: [pgpool-general: 1701] poor performance w/ pgpool
> 
>> I haven't had a chance to put any performance monitoring in place but I can say for certain that my application is unable to keep up with our expected load when I use pgpool.  If I point the application directly to postgres we are able to process the expected load. 
>> 
>> Here is the setup
>> 
>> node1
>> primary pgpool
>> primary postgres
>> 
>> node2
>> backup pgpool
>> async streaming replication postgres
>> 
>> num_init_children = 100
>> max_pool = 9 
>> postgres max set to 1000
>> 
>> (load balance mode turned off, watchdog enabled)
>> 
>> client (jdbc) is doing 100% writes 0% reads its doing ~1000 inserts per second.
>> 
>> I am going to start putting in more monitoring right now, but has anyone else seen this?  Are there tweaks to pgpool I should be making?
> 
> Pgpool does nothing good for this type of load. It just gives an
> overhead to read packets from clients and foward to PostgreSQL, and
> vice versa.
> 
> However there are something to mitigate the overhead:
> 
> - Do not use SSL. To process SSL connections, pgpool needs to work hard.
> 
> - Give pgpool enough CPU resource. In your configuration pgpool has to
>   share CPU resource with PostgreSQL. Adding CPU core might be a good
>   idea.
> 
> - Use high speed network device.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
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