[Pgpool-general] Error: pool_add_sent_message: portal "" already exists

[Jonathan Regeimbal]

Hi Tatsuo,

I am running 3.0.3-2 at the moment.  That could be an option, however I 
do not have experience with CVS.  Do you anticipate that there will be 
another stable package released in the 3.0.X series?  If not, is it 
worth trying 3.1 alpha2?  This is for a production cluster that we hope 
to go live with in the next few days.

Thanks,

Jonathan


On 5/17/2011 5:23 AM, Tatsuo Ishii wrote:
> I'm not sure what pgool-II version you are using but if you are using
> 3.0.x, you might want to try the lastest pgpool-II-3.0-STABLE tree
> from the source repository.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
>
>> Hi everyone,
>>
>> I'm looking for help (and hopefully a solution) involving an error I
>> am getting while using PGPool2 in master/slave +LB mode on top of PG9
>> in streaming replication mode.  In general Pgpool2 is working great,
>> but as noted in the subject every so often we get portal errors back
>> from PGPool2 that result in internal server errors.  When our
>> application is connected directly to PG9, these errors do not occur.
>> Digging deeper these errors seem to commonly occur in PGPool2 while in
>> Load Balance mode, but only sometimes are they reported back to DBI as
>> an error.  Here is an excerpt from Pgpool2's debug log.
>>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9083: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9080: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9082: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9085: pool_add_sent_message: portal "" already exists
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9085: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9078: pool_add_sent_message: portal "" already exists
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9051: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9078: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9080: pool_add_sent_message: portal "" already exists
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 9080: Execute: portal name<>
>> May 13 21:13:22 ip-10-119-14-100 pgpool: 2011-05-13 21:13:22 DEBUG:
>> pid 8910: pool_add_sent_message: portal "" already exists
>>
>> On occasion Pgpool2 logs this error at the LOG level in addition to
>> the DEBUG level:
>>
>> May 13 20:39:12 web2 pgpool: 2011-05-13 20:39:12 LOG: pid 8107:
>> pool_send_and_wait: Error or notice message from backend: : DB node
>> id: 0 backend pid: 8157 statement: P message: portal "" does not exist
>>
>> And when that happens our application receives the error too (And
>> generates an Internal server error)
>>
>> This is the error as logged by apache2, which would have originated
>> from DBI and DBD::Pg:
>>
>> [Fri May 13 20:39:152011] -e: DBD::Pg::st execute failed: ERROR:
>> portal "" does not exist at /home/www/directory_to_module/a_module.pm
>> line 514.
>>
>> What I'm looking for is insight into what this error means, and help
>> determing whether this is user error in our configuration or usage of
>> PGPool2, or a potential bug in PGPool2. I'd like to note in case it
>> helps, that when Load balancing is turned off, all portal errors go
>> away. However, in our application we need loadbalancing as our
>> application has reached a point where it peak traffic demands better
>> database performance, and continues to grow)
>>
>> I could post up our pgpool.conf, but it's nothing special, but if it
>> helps let me know and I'll send it out.
>>
>> Thanks for any help or insight!
>>
>> -Jonathan
>>
>> -- 
>> Jonathan Regeimbal
>> The Richard Group
>> w: 703.584.5808
>> c: 540.907.5116
>> e: jlregeim at gmail.com