[pgpool-general: 850] Re: pgpool just hangs up after reaching "num_init_children" connections
ishii at postgresql.org
Fri Aug 3 15:00:11 JST 2012
> Yes, I read that FAQ. But I could also clearly observe that if it reaches
> "num_init_children" concurrent sessions, then it is not even allowing
> existing/already connected users a chance to disconnect, though. So, it
> becomes like a deadlock situation.
Not sure. Because I don't know your applications behavior.
> In order to set the right value for "num_init_children", we want to find out
> the *maximum connection* reached at any given timeframe from pgpool log, in
> case if we decide to increase "num_init_children" value. Is it possible to
> determine this information from pgpool?
If you see the out put of ps command, it is easy to find out such a
situation because there would be no pgpool process something like this
if all pgpool child process are busy(or waiting for frontend exits):
apache 17236 0.0 0.0 63408 1220 ? S 11:57 0:00 pgpool: wait for connection request
However even if you want to find the number from pgpool log, it's
would be fairly easy. There's a counter in shared memory area:
Req_info->conn_counter. See connection_count_up(void):child.c.
SRA OSS, Inc. Japan
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