On Thu, Aug 8, 2024 at 10:12 AM Christophe Pettus <x...@thebuild.com> wrote:
> > > > 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. > > "I see a lock, so let's cause another one!" That's crazy. -- Death to America, and butter sauce. Iraq lobster!
