Re: many sessions wait on LWlock WALWrite suddenly

LWLock always shows up in the case where you have too many concurrent
active connections.  Do a select from the pg_stat_activity table where
state in ('idle in transaction','active'); Then count how many CPUs you
have. If the sql query count returned is greater than 2-3 times the
number of CPUs, you probably have a CPU overload problem and your
solution may be to add a connection pooler between the client and the DB
server.  This is all due to the nature of how PG is architected: every
connection is a process, not a thread.

Regards,
Michael Vitale

James Pang wrote on 4/11/2025 10:36 AM:
>    pgv14.8 , during peak time, we suddenly see hundreds of active
> sessions waiting on LWlock  WALWrite at the same time, but we did not
> find any issue on storage .
> any suggestions ?
>
> Thanks,
>
> James


Regards,

Michael Vitale

Michaeldba@sqlexec.com <mailto:michaelvitale@sqlexec.com>

703-600-9343