Tomcat doesn't stop. How can I debug this?

Question

I have a Tomcat 7 running in Linux that I start via $CATALINA_HOME/bin/startup.sh and shutdown via $CATALINA_HOME/bin/shutdown.sh

Answer 1

I had the exact same problem. Sometimes, the command ./shutdown.sh does not stop the tomcat process, and its java process stays in the running processes.

I had solved this problem using the Tomcat version in the Ubuntu's software repositories, by:

sudo apt-get install tomcat7

After installing it from package manager and configuring some settings, I did not have any problems on stopping/starting Tomcat. I used this command to stop, and it never failed:

service tomcat7 stop

which is nearly the same as

/etc/init.d/tomcat7 stop

Using this command runs the code block from the init script, specifically, the codes from the file /etc/init.d/tomcat7. So I looked into it to see what it does to always kill the tomcat process succesfully. Here is the code block that runs when you use service tomcat7 stop command:

log_daemon_msg "Stopping $DESC" "$NAME"

        set +e
        if [ -f "$CATALINA_PID" ]; then
                start-stop-daemon --stop --pidfile "$CATALINA_PID" \
                        --user "$TOMCAT7_USER" \
                        --retry=TERM/20/KILL/5 >/dev/null
                if [ $? -eq 1 ]; then
                        log_progress_msg "$DESC is not running but pid file exists, cleaning up"
                elif [ $? -eq 3 ]; then
                        PID="`cat $CATALINA_PID`"
                        log_failure_msg "Failed to stop $NAME (pid $PID)"
                        exit 1
                fi
                rm -f "$CATALINA_PID"
                rm -rf "$JVM_TMP"
        else
                log_progress_msg "(not running)"
        fi
        log_end_msg 0
        set -e
        ;;

The important part is this:

start-stop-daemon --stop --pidfile "$CATALINA_PID" \
                            --user "$TOMCAT7_USER" \
                            --retry=TERM/20/KILL/5 >/dev/null

This means "retry stopping until the process is stopped. Here is the --retry command documentation from start-stop-daemon manual:

   -R|--retry timeout|schedule
          With  --stop,  specifies  that  start-stop-daemon  is  to  check
          whether  the  process(es)  do  finish.  It will check repeatedly
          whether any matching processes are running, until none are.   If
          the  processes  do  not exit it will then take further action as
          determined by the schedule.

          If timeout is specified instead of schedule  then  the  schedule
          signal/timeout/KILL/timeout  is used, where signal is the signal
          specified with --signal.
          ...

So, --retry=TERM/20/KILL/5 means "Send TERM signal to the process, wait 20 seconds, if it's still running, send KILL signal, wait 5 seconds, if it's still running, there is a problem.

This means you can configure the tomcat to run as a deamon and use a command like this, or write a script to do that kind of action to stop tomcat, or just use Ubuntu and get the tomcat from the package manager.