Message queues on Linux

These are the suggested settings to place in the configuration file /etc/sysctl.conf.

kernel.msgmni=128               #Max # of msg queue identifiers
kernel.msgmnb=163840            #Size of message queue
kernel.msgmax=40960             #Max size of a message

On Red Hat, the new settings are used after you restart the computer.
On SuSE, issue the command chkconfig boot.sysctl on, and then reboot.
To check that the new settings have been applied, issue the command sysctl -a.

The MSGMNI variable determines the maximum number of message queue identifiers system wide. This is typically set to 128 which is sufficient for the typical number of concurrent requests expected to be processed.