I have a Jboss Application running on a Linux machine connecting to a Queue Manager on Websphere MQ running on an AIX box. I have a cron script that is executed every Sunday evening to stop (shutdown.sh) and start (run.sh) this JBoss application. About three and a half hours before this cron script runs, the Queue manager that the application is connecting to gets restarted for backup purposes. There is a 15 minutes delay between the Shutdown.sh and the run.sh. The problem I have is that sometime the Shutdown.sh script hangs and doesn't stop the application, then 15 minutes later, the run.sh script gets executed and then I have two instances running. I can force it to stop buy doing a kill -9, But I just want to find out whats causing this.