[pgpool-general: 1703] Re: poor performance w/ pgpool

[Tatsuo Ishii]

> 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