Re: lwlock:LockManager wait_events

You may find this helpful, the advice is not specific to RDS.

https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/wait-event.lw-lock-manager.html

HTH.

On Fri, 25 Oct 2024 at 18:36, Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at> wrote:

> On Fri, 2024-10-25 at 14:36 +0800, James Pang wrote:
> > we faced into a lot of lwlock:LockManager wait-events , all of these
> queries are "select ..." ,
> > there are other several session are doing DML, insert/update/delete on
> same table.
> > Did these DML transactions holding "transactionid" and "tuple" lock
> blocking "select" on lwlock:LockManager ?
>
> This is not about waiting for a lock. Rather, it means that very many
> sessions are trying
> to take a lock. They have to grab the lock manager to take a lock, and
> the competition for
> that resource is the bottleneck.
>
> It is hard to say what is the root cause without further analysis, but
> very often the
> cause is that you have too many connections to the database. Using an
> effective connection
> pool *might* solve that particular problem.
>
> Yours,
> Laurenz Albe
>
>
>