[Pgpool-general] Pgpool 3.1 errors

[Guillaume Lelarge]

On Tue, 2011-10-04 at 10:39 +0200, Olivier NOEL wrote:
> Hi,
> 
> I compiled and installed pgpool 3.1 on Debian Wheezy yesterday. No
> compile errors.
> 
> But I have a LOT of errors :
> 
> Oct  4 10:09:48 pgpool01 pgpool: 2011-10-04 10:09:48 ERROR: pid 1198:
> Child process 7712 was terminated by segmentation fault
> Oct  4 10:09:48 pgpool01 pgpool: 2011-10-04 10:09:48 ERROR: pid 1198:
> Child process 8249 was terminated by segmentation fault
> Oct  4 10:09:48 pgpool01 pgpool: 2011-10-04 10:09:48 LOG:   pid 9698:
> do_child: failback event found. restart myself.
> Oct  4 10:09:48 pgpool01 pgpool: 2011-10-04 10:09:48 LOG:   pid 9699:
> do_child: failback event found. restart myself.
> Oct  4 10:09:48 pgpool01 kernel: [30451.414053] pgpool[7712]: segfault
> at 0 ip 00000000004495b0 sp 00007fff942728c0 error 4 in
> pgpool[400000+dc000]
> Oct  4 10:09:48 pgpool01 kernel: [30451.415038] pgpool[8249]: segfault
> at 0 ip 00000000004495b0 sp 00007fff942728c0 error 4 in
> pgpool[400000+dc000]
> Oct  4 10:10:08 pgpool01 kernel: [30471.410705] pgpool[7880]: segfault
> at 0 ip 00000000004495b0 sp 00007fff942728c0 error 4 in
> pgpool[400000+dc000]
> Oct  4 10:10:08 pgpool01 pgpool: 2011-10-04 10:10:08 ERROR: pid 1198:
> Child process 7880 was terminated by segmentation fault
> Oct  4 10:10:08 pgpool01 pgpool: 2011-10-04 10:10:08 LOG:   pid 9705:
> do_child: failback event found. restart myself.
> 
> And a LOT of :
> 
> pid 1465: ProcessFrontendResponse: failed to read kind from frontend.
> frontend abnormally exited
> 
> Pgpool 3.1 on Debian Wheezy, compiled with postgresql-server-dev-9.1
> Postgresql server 9.1 on FreeBSD 8.2 in streaming replication, 1
> master 2 slaves (replication is working)
> 
> Pgpool kept disconnecting Postgres backends randomly. It didn't find
> at first the master node, I had to rename the node from
> backend_hostname6 to backend_hostname0.
> Another weird thing is that pgpool connects to the postgres backends
> with "nobody" instead of "postgres".
> 
> I can't use pgpool 3.0.4 either (version of pegpool on Debian Wheezy),
> because I get "portal" errors :
> ERROR:  portal "" does not exist
> ERROR:  portal "pgpool_error_portal" does not exist
> 
> Config file is attached.
> 

The conf file you're using is a 3.0 one. I hope you don't use that for
3.1, as it may not work at all.

Your num_init_children seems way too big. 1000... it means pgpool will
launch 1000 subprocesses when it starts. Kinda crazy :) Moreover, with
the max_pool at 8, it means pgpool can have 8000 connections to your
PostgreSQL server. Have you really configured PostgreSQL with a
max_connections of 8000?

On the load balancing configuration, you didn't deny load balancing of
nextval and setval, which is obviously an error.

On your backend configuration, you set backend_hostname0, and then go
directly to backend_hostname7. It may be an issue. Try to set them in
order (O, then 1, then 2). Not sure it has a real value, I never tried
that, but it works for me when they are set in order, and without hole.


-- 
Guillaume
  http://blog.guillaume.lelarge.info
  http://www.dalibo.com