Thread: SOMAXCONN, MaxBackendID and Postgres

hi wondered if anyone can help:-

O/S  S.u.s.e linux 6.0
kernel 2.0.36
postgres 6-4-2 

I'm trying to increase the maximum number of connections  on the operating
system which invovles altering the SOMAXCONN and patching certain files. I've
done that but im still limited by postgres. I found that the ./configure file
was pulling in a different version of socket.h from the operating system. After
altering that I still had the same problem.  I've also increase the
MaxBackendID and that still doesn't help. Is there any
more documentation on SOMAXCONN or has anybody else had this problem. I know
unix based O/S's have 128 connections but I need to increase this considerably.
Currently im aming for about 512 connections. Is there any draw backs I should
be aware of? any help on this is greatly appreciated. 

Thanks guys n gals,Stuart 


+-=-=-=-=-=-=-=-StOo-=-=-=-=-=-=-=-+

Stuart Hodgkinson - Software Engineer

Comodo Technology Design

StOo <stuart@comodo.net> writes:
> O/S  S.u.s.e linux 6.0
> kernel 2.0.36
> postgres 6-4-2 

> I'm trying to increase the maximum number of connections  on the operating
> system which invovles altering the SOMAXCONN and patching certain
> files.

Changing the max number of backends in 6.4.* is pretty painful.  I'd
suggest updating to 6.5.1 --- you can set the max to as high as 1024
without even recompiling.

Whether your kernel will support that many is another question.  Aside
from the connections themselves, you need adequate swap space, file
table slots, etc to support that many processes.  You will also need
larger-than-typical limits on the size of the shared memory block and
on the max number of semaphores.
        regards, tom lane