Re: PROBLEM Service Alert: hostname/check_postgres_old_transaction is CRITICAL ** - Mailing list pgsql-general

From Adarsh Sharma
Subject Re: PROBLEM Service Alert: hostname/check_postgres_old_transaction is CRITICAL **
Date
Msg-id CAGx-QqJLFjdW1fudJkJZk5S_N44dBSNdBpk_+Vavt2K2Pun8sA@mail.gmail.com
Whole thread Raw
In response to Re: PROBLEM Service Alert: hostname/check_postgres_old_transaction is CRITICAL **  (Jan-Pieter Cornet <johnpc@xs4all.net>)
List pgsql-general
Thanks Jan.!! Will check and update you all the findings.

Cheers

On Sat, Sep 20, 2014 at 4:17 AM, Jan-Pieter Cornet <johnpc@xs4all.net> wrote:
On 2014-9-19 20:33 , Adarsh Sharma wrote:
> It returns approx *311 MB* data to the client servers.
>
> root > netstat -p | grep 45355
> tcp        0 1531648 localhost:5499              localhost:48848             ESTABLISHED 45355/postgres
>
> root > strace -p 45355
> -- Remain stuck for *2-3 *hours
> read(306, "\30\0kB\3\0\0\0\0\0\377\5\0\0\26\0\0\0\2\0\0\0\30\0+\264\3\0\0\0\0\0"..., 8192) = 8192
> sendto(10, "4174\0\0\0\0041535D\0\0\0\30\0\2\0\0\0\006248710\0\0\0"..., 8192, 0, NULL, 0
>
> Then after 2-3 hours it got completed automatically with below stacktrace :
>
> # strace -p 45355
> Process 45355 attached - interrupt to quit
> sendto(10, "4174\0\0\0\0041535D\0\0\0\30\0\2\0\0\0\006248710\0\0\0"..., 8192, 0, NULL, 0
>
>         ) = -1 ECONNRESET (Connection reset by peer)

I'd guess that the receiving program crashes. It might not be able to stomach the 311 MB that's being sent to it, maybe it's expanding, and swapping, until it's killed by the OOM killer?

Doesn't look like a postgres problem to me. postgres is stuck trying to send data... try stracing the client to see what it does? (use "lsof -i :48848" or whatever the port number of the remote is to find the pid).

--
Jan-Pieter Cornet <johnpc@xs4all.net>
"Any sufficiently advanced incompetence is indistinguishable from malice."
    - Grey's Law


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