> On Aug 7, 2024, at 10:34, Costa Alexoglou <co...@dbtune.com> wrote:
>
> Hey folks,
>
> I noticed something weird, and not sure if this is the expected behaviour or
> not in PostgreSQL.
>
> So I am running Benchbase (a benchmark framework) with 50 terminals (50
> concurrent connections).
> There are 2-3 additional connections, one for a postgres-exporter container
> for example.
>
> So far so good, and with a `max_connections` at 100 there is no problem. What
> happens is that if I execute manually `VACUUM FULL` the connections are
> exhausted.
VACUUM FULL takes an exclusive lock on the table that it is operating on. It's
possible that a connection becomes blocked on that exclusive lock waiting for
the VACUUM FULL to finish, the application sees the connection stopped and
fires up another one (this is common in container-based applications), that one
blocks... until all of the connections are full of queries waiting on that
VACUUM FULL.
