Re: too many clients already

On 4/2/20 8:06 AM, Abraham, Danny wrote:
> Hi,
>
> Will appreciate a hint here.
>
> Running on a big and stressed AIX platform and receiving lots of "CDTFATAL: sorry, too many clients already"
> and transient difficulty to log in.
>
> Happens on all PG versions (Tested 9.5,10.4,11.5)
>
> Big installation: max_connections is 1200, shared_buffers is 2GB
>
> But .. select count(*) from pg_stat_activity is only 66.

On the chance pg_stat_activity is lying to you what does:

ps ax | grep post

show for backends?

For example:

ps ax | grep post
1217 ? Ss 0:00 /usr/lib/postfix/bin//master -w
1233 ? S 0:00 /usr/local/pgsql12/bin/postmaster -D
/usr/local/pgsql12/data
1253 ? Ss 0:00 postgres: logger
1277 ? Ss 0:00 postgres: checkpointer
1278 ? Ss 0:00 postgres: background writer
1279 ? Ss 0:00 postgres: walwriter
1280 ? Ss 0:00 postgres: autovacuum launcher
1281 ? Ss 0:00 postgres: stats collector
1282 ? Ss 0:00 postgres: logical replication launcher
*4693 ? Ss 0:00 postgres: aklaver task_manager [local] idle
*4907 ? Ss 0:00 postgres: aklaver production [local] idle

>
> Thanks
>
> Danny
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com