Increase maxuproc value

Linux and Unix-Like Red Hat
1

Hi Guys,

I am running RHEL6 and now my processes reach maximum limit.

How do I increase the maxuproc value?

Can I increase the value without rebooting the server?

Thanks in advance...

Please Help!!!

2

Hello Phuti,

It would be better to know why you have reached the limit rather than just increasing it. How have you set this limit so far, or is it the default? How many processes do you have, and why do you think you have run out?

My main concern is that something has gone into a loop and is generating processes all the time, so if increasing the limit without a boot is possible, then you will just have the problem growing. The limit is there to try to protect your system from something going wrong.

Has something recently changed for this server, e.g. has it now become production and therefore it's under untested load perhaps?

I think that the value can only be set at boot time, so it might be (I'd need to check) an update to the configuration, a kernel build and a boot to bring it in. If it was Solaris then i think it's simply a file update, but again a boot to bring it in. I think that AIX has them all set to maximum anyway.

If you can elaborate a little more, then we might be able to find a better solution.

Kind regards,
Robin

1 Like
3

iirc, it's either /etc/security/limits.conf or a sysctl value.

1 Like
4

It is nproc in /etc/security/limits.conf or /etc/security/limits.d/*
This per-user limit is for threads (LWPs, light-weight-processes) rather than processes.
RHEL 6 ships with

 rpm -qf /etc/security/limits.d/90-nproc.conf
pam-1.1.1-20.el6.x86_64
 cat /etc/security/limits.d/90-nproc.conf
# Default limit for number of user's processes to prevent
# accidental fork bombs.
# See rhbz #432903 for reasoning.

*          soft    nproc     1024
root       soft    nproc     unlimited

We set this to 9000 on our servers.

1 Like
5

You might want check out this thread regarding nproc in RHEL 6.3 or later.

https://bugzilla.redhat.com/show_bug.cgi?id=919793

I was scratching my head other day when java app server failed to work properly cause of this bug.

1 Like
6

Thanks guys for the replies...my application is not closing the sessions.

It will not be useful for me to increase the nproc.

We have to deal with the root cause.

Thanks a lot