[Pgpool-general] unexpected EOF on client connection

[Tatsuo Ishii]

> On Tue, Sep 13, 2011 at 8:48 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>>> On Mon, Sep 12, 2011 at 6:47 PM, Lonni J Friedman <netllama at gmail.com> wrote:
>>>> On Mon, Sep 12, 2011 at 6:39 PM, Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>>>>>>> I couldn't find anything possibly related to your problem at a first
>>>>>>> grance(in theory client_idle_limit and authentication_timeout are not
>>>>>>> related but you might want to change them to see anything could be
>>>>>>> changed).
>>>>>>
>>>>>> OK, I'll give that a try.  Should I just try increasing them by 10 or 20s?
>>>>>
>>>>> I'd suggest giving them 0. This will prevent to initiate those
>>>>> functionalities which the directives are related.
>>>>>
>>>>> Also you hve child_life_time being 300. I don't expect this is related
>>>>> but could you set it to 0 and see anything gest changed for just in
>>>>> case?
>>>>
>>>> OK, i'll make those changes tomorrow (its late in the day here, and I
>>>> don't want to introduce potential problems in the middle of the night
>>>> when no one is closely monitoring the server), and let you know if
>>>> they have any impact.
>>>
>>>
>>> client_idle_limit was already 0.  I set authentication_timeout=0 and
>>> child_life_time=0, and restarted pgpool, however that had no impact.
>>> I'm still seeing:
>>> 26323 2011-09-13 09:28:19 PDT LOG:  unexpected EOF on client connection
>>> 3933 2011-09-13 09:36:20 PDT LOG:  unexpected EOF on client connection
>>
>> Humm. Is it possible that those connections do not come from pgpool
>> process?
> 
> I'm pretty sure that's not the case as the messages stop whenever
> pgpool isn't running, they were not present prior to using pgpool, and
> pg_hba.conf is setup such that the database servers only accept
> connections from each other, and the server running pgpool.  None of
> these servers have normal users connected directly to them (such as
> with ssh), nor are they running anything that would connect to the
> database as a client.  Also, the volume of these messages are such
> that something significant has to be causing them.  Last night, in the
> span of 5 minutes, there were 117 of these messages.

Ok. I would like to narraow down the reason why we have "unexpected
EOF on client connection" message frequently. I think currently there
are two possiblities:

1) pgpool child was killed by some unknown reason(we can omit
   segfault case because you don't see it in the pgpool log)

2) pgpool child disconnects to PostgreSQL in ungraceful manner

For 1) I would like to know if pgpool child process are fine since
they are spawned. Are you seeing any pgpool child process disappeared
since pgpool started?
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp