Обсуждение: "too many clients" and no cure

Hi,

I experience some trouble with my PG server. I get the error message
"too
many clients". Ok, so I checked the manual and adjusted the
max_connections and shared_buffers, but still the server denies access,
if
there are about 100 connections. I just recently increased the shared
buffers from 10000 to 50000 and the system shared memory fom 128m to
about
800m. Still the error occurs at 100 active connections.

Here's some system info:
OS is SuSE Linux 9.1 (kernel 2.6.7-040722)
I have 1GB of RAM.
PG is 7.4.2
Parameters in postgresql.conf:
max_connections = 500
shared_buffers = 50000
sort_mem = 2048

sysctl -a | grep shm
kernel.shmmni = 134217728
kernel.shmall = 805306368
kernel.shmmax = 805306368

ipcs -ls
------ Semaphore Limits --------
max number of arrays = 128
max semaphores per array = 250
max semaphores system wide = 32000
max ops per semop call = 100
semaphore max value = 32767

Thanks,
Tom

postgresql@thomasbache.de writes:
> I experience some trouble with my PG server. I get the error message
> "too many clients". Ok, so I checked the manual and adjusted the
> max_connections and shared_buffers, but still the server denies
> access, if there are about 100 connections. I just recently increased
> the shared buffers from 10000 to 50000 and the system shared memory
> fom 128m to about 800m. Still the error occurs at 100 active
> connections.

It sounds like you forgot to restart the postmaster after changing
postgresql.conf.  This is one of the parameters that is frozen at server
start ...

            regards, tom lane

> It sounds like you forgot to restart the postmaster after changing
> postgresql.conf.  This is one of the parameters that is frozen at
server
> start ...

No, I did restart the postmaster. Actually more than once. I do not have
to restart the server after changing kernel parameters with sysctl, do
I? Do you have any other ideas? I'm having trouble since a week or so
...

postgresql@thomasbache.de writes:
>> It sounds like you forgot to restart the postmaster after changing
>> postgresql.conf.  This is one of the parameters that is frozen at
>> server start ...

> No, I did restart the postmaster. Actually more than once.

In that case, maybe you edited the wrong copy of postgresql.conf?
Try checking "SHOW max_connections" to verify what the postmaster
thinks the value is.

> I do not have to restart the server after changing kernel parameters
> with sysctl, do I?

I don't think kernel limits would lead to "too many clients" --- you'd
be getting different sorts of failures if the problem were in that area.

            regards, tom lane

> In that case, maybe you edited the wrong copy of postgresql.conf?
> Try checking "SHOW max_connections" to verify what the postmaster
> thinks the value is.

Hmm, it said it still had 100. Even though the postgresql.conf stayed
unchanged, after yet another restart it works. Funny.

> I don't think kernel limits would lead to "too many clients" --- you'd
> be getting different sorts of failures if the problem were in that
area.

Thanks a lot !

Tom