Is it dead or is it unresponsive
ps -ef | grep wiki to see if the Tomcat JVM is still alive or not.
If it's alive...
- Get the heap statics with "sudo jmap -heap PID"
- Get the stack dump if you can. "sudo jstack -F PID". This can fail to respond.
If it's dead...
hs_err_pid*.log files and capture it.