On Fri, 2022-05-20 at 12:15 +0200, Andreas Kretschmer wrote: > On 20 May 2022 10:27:50 CEST, aditya desai <admad123@xxxxxxxxx> wrote: > > One of our applications needs 3000 max_connections to the database. > > Connection pooler like pgbouncer or pgpool is not certified within the > > organization yet. So they are looking for setting up high configuration > > Hardware with CPU and Memory. Can someone advise how much memory and CPU > > they will need if they want max_conenction value=3000. > > Pgbouncer would be the best solution. CPU: number of concurrent connections. > RAM: shared_buffer + max_connections * work_mem + maintenance_mem + operating system + ... Right. And then hope and pray that a) the database doesn't get overloaded and b) you don't hit any of the database-internal bottlenecks caused by many connections. I also got the feeling that the Linux kernel's memory accounting somehow lags. I have seen cases where every snapshot of "pg_stat_activity" I took showed only a few active connections (but each time different ones), but the amount of allocated memory exceeded what the currently active sessions could consume. I may have made a mistake, and I have no reproducer, but I would be curious to know if there is an explanation for that. (I am aware that "top" shows shared buffers multiple times). Yours, Laurenz Albe
