Unexpected Signal 11

Some people have been seeing OpenNMS die, sometimes frequently, sometimes after a month. In each case, output.log has a Java VM error message that references “Unexpected Signal 11”.

I haven’t seen it on any of my machines, but I have seen it at some client sites. Recent Wrolf Courtney was having the problem quite regularly. He got a tip from Bill Ayres to increase his “ulimit” values.

In opennms.sh change the following line:

ulimit -s 2048


ulimit -s 8192

and add the line

ulimit -n 10240

Wrolf said that this solved his problem, and it makes sense to me. I have seen strange “OutOfMemory” and “TooManyOpenFiles” errors when the JVM gets constrained by the O/S, and with RHL 8.0 they have added pam_limits by default, so my guess is that I am not seeing it since I tend to still run on Red Hat Linux 7.3

Anyway, if you are seeing this problem, you may want to check out that change. I have submitted it to CVS HEAD, and Wrolf has updated the FAQ.