Linux software debug TIPS
How many file descriptors opened by my java application?
# Get hte java process ID ps -ef | grep java # Count filedescriptors opened by this java process cd /proc/<java_PID>/fd ls -l | wc -l # And if you want to verify what your java application has opened, just inside the same directory ls -l # if you want to see more details about filedescriptors opened lsof -a -p <java_PID>
Process listening on a port
Beware that apache ssl virtualhost *:443 with lsof or netstat will appear as a name *:https not *:443
lsof -i | grep 8009 lsof -i | grep https netstat -pao |grep 8009 netstat -pao |grep https