Re: Getting error "too many clients already" despite having a db connection limit set

You might want to explore pgpool and pgbouncer. Depending in your use case
you might want to glue them togeter.

On Mon, Jun 16, 2025, 10:39 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> adolfo flores <adolfoflores2211(at)gmail(dot)com> writes:
> > I hope you can help me with an issue we're experiencing. We have an app
> > running on Kubernetes that opens a huge number of connections within a
> > couple of seconds.
>
> You need to fix that app to be less unfriendly, or maybe put it behind
> a connection pooler.
>
> > Is it expected behavior to reach the max_connections limit when that app
> > opens many connections in a short period of time, even if a connection
> > limit is set for that database and everything else uses no more than 10%
> of
> > the max_connections?
>
> It takes a finite amount of time for a new backend process to figure
> out which database it's supposed to connect to and then detect whether
> the per-DB connection limit is exceeded. In the meantime, that
> session does count against the global limit, so yeah this isn't
> surprising if the connection arrival rate is high enough.
>
> regards, tom lane
>
>
>