[pgpool-general: 1243] Re: PGPool Stops Accepting Connections Without Errors

[Lonni J Friedman]

Which Linux distro are you running?
Which version of pgpool?

On Thu, Dec 6, 2012 at 4:16 PM, Nick Webb <nickw at redwireservices.com> wrote:
> All,
>
> Not sure this is a problem with PGPool or not, but every 3-4 days our
> PGPool instance just stops accepting postgres connections, they all
> time out.  When this situation occurs, the system is not particularly
> busy, and CPU, memory, and number of current connections are all
> normal.  What's more, connecting to the backends directly from the
> PGPool host also works fine, and is quite snappy (via psql), but no
> connections to PGPool work.  Restart pgpool and things are back up and
> running in seconds.
>
> Looking at the log, there are no errors or warnings, not sure where to
> look next.  I checked all the usual Linux log suspects, and nothing
> else was going on (like maxing out some system resource, etc.).
>
> Here is the log immediately before and after the "hang up", which
> happened approximately 19:42 UTC:
> Dec  6 19:23:58 PGLB pgpool[3210]: statement: SELECT
> Dec  6 19:23:58 PGLB pgpool[3210]: DB node id: 1 backend pid: 22221
> statement: SELECT
> Dec  6 19:23:58 PGLB pgpool[3210]: statement: SELECT
> Dec  6 19:23:58 PGLB pgpool[3210]: DB node id: 1 backend pid: 22221
> statement: SELECT
> Dec  6 19:23:58 PGLB pgpool3210]: statement: SELECT
> Dec  6 19:23:58 PGLB pgpool[3210]: DB node id: 1 backend pid: 22221
> statement: SELECT
> Dec  6 19:24:24 PGLB pgpool[26744]: statement:  DISCARD ALL
> Dec  6 19:24:24 PGLB pgpool[26744]: DB node id: 0 backend pid: 27232
> statement:  DISCARD ALL
> Dec  6 19:24:24 PGLB pgpool[26744]: DB node id: 1 backend pid: 20837
> statement:  DISCARD ALL
> Dec  6 19:24:24 PGLB pgpool[26744]: connection received: host=3.myhost.com=43275
> Dec  6 19:42:06 PGLB pgpool[26782]: statement:  DISCARD ALL
> Dec  6 19:42:06 PGLB pgpool[26782]: DB node id: 0 backend pid: 28378
> statement:  DISCARD ALL
> Dec  6 19:42:06 PGLB pgpool[26782]: DB node id: 1 backend pid: 21991
> statement:  DISCARD ALL
> Dec  6 19:42:06 PGLB pgpool[26782]: connection received:
> host=www.myhost.com port=57636
>
> [ note the lack of entries after this point, until the restart,
> despite many attempted connections ]
>
> Dec  6 19:43:59 PGLB pgpool[26276]: received fast shutdown request
> Dec  6 19:44:00 PGLB pgpool[13237]: connection received:
> host=2.myhost.com port=5973
> Dec  6 19:44:00 PGLB pgpool[13234]: pgpool-II successfully started.
> version 3.1.5 (hatsuiboshi)
>
> Next time I'll run a "show pool_pools", but it's hard for me to
> believe that all the slots were full.