[pgpool-general: 3525] Re: Amazon EC2 Load Balancer health check kills pgPool node

[Scott Rankin]

Would it be possible to just log the un-graceful shutdown but not crash
the pgPool process?



On 3/16/15, 11:28 PM, "Tatsuo Ishii" <ishii at postgresql.org> wrote:

>I guess pgpool-II complains that EC2 Elastic Load Balancer does not
>disconnect the session in a grace manner. As far as I know, EC2
>Elastic Load Balancer supports HTTP/HTTPS but does not support the
>PostgreSQL protocol. So I think there is not too much that pgpool-II
>can do.
>
>Best regards,
>--
>Tatsuo Ishii
>SRA OSS, Inc. Japan
>English: http://www.sraoss.co.jp/index_en.php
>Japanese:http://www.sraoss.co.jp
>
>> Hi all,
>>
>> I’m running pgPool 3.4.1 on a pair of CentOS 6.6 boxes at AWS, and I
>>have an EC2 Elastic Load Balancer configured to balance requests between
>>them.  I have health checks set up on the load balancer, and I’ve
>>noticed that every time I get a health check, the pgPool worker process
>>that services that request dies.  Here’s an excerpt from the log:
>>
>> pgpool[389]: [951-2] 2015-03-16 18:14:36: pid 389: DETAIL: EOF
>>encountered with frontend
>> pgpool[27]: [749-1] 2015-03-16 18:14:36: pid 27: LOG: child process
>>with pid: 389 exits with status 256
>> pgpool[27]: [750-1] 2015-03-16 18:14:36: pid 27: LOG: fork a new child
>>process with pid: 480
>>
>> pgpool[502]: [733-1] 2015-03-16 18:15:06: pid 502: FATAL: unable to
>>read data from frontend
>> pgpool[502]: [733-2] 2015-03-16 18:15:06: pid 502: DETAIL: EOF
>>encountered with frontend
>> pgpool[28]: [759-1] 2015-03-16 18:15:06: pid 28: LOG: child process
>>with pid: 502 exits with status 256
>> pgpool[28]: [760-1] 2015-03-16 18:15:06: pid 28: LOG: fork a new child
>>process with pid: 524
>>
>> This was happening every 30 seconds.  When I change the health check to
>>be every 5 minutes, the child process dying also moved to every 5
>>minutes.  I don’t have a whole lot of control over the health check #|
>>it’s a TCP connection on the pgPool port.
>>
>> Has anybody seen something like this before?
>>
>> Thanks,
>> Scott
>>
>> SCOTT RANKIN
>> Vice President, Technology
>> Motus, LLC
>> Two Financial Center, 60 South Street, Boston, MA 02111
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