Apache hangs due to no way to acquire mutexes

[alsroot]

At some point, apache on sunjammer stops reflecting on requests and even SIGTERM can't stop processes, only SIGKILL.

The logs say:

[Fri Nov 25 07:29:17 2011] [emerg] (22)Invalid argument: couldn't grab the accept mutex

[alsroot]

I've increased these values (by guessing) in /etc/sysctl.d/99-apache.conf:

• semmsl from 250 to 500
• semmni from 128 to 256

[alsroot]

Replying to alsroot:

I've increased these values (by guessing) in /etc/sysctl.d/99-apache.conf:

• semmsl from 250 to 500
• semmni from 128 to 256

s/semmsl/semmns/

[bernie]

We can check if sys5 semaphores are really running out with "ipcs -s".

I also have a trick to cleanup the semaphores globally:

for i in ipcs -s | grep www-data | awk '{print $2}'; do ipcrm -s $i; done

[bernie]

Oops, the wiki syntax mutilated my poor one-liner.

for i in `ipcs -s | grep www-data | awk '{print $2}'`; do ipcrm -s $i; done