OOM restart script

#!/bin/bash

(

# we need to close all existing file descriptors, because
# JVM passes them all on fork, and we end up holding up
# listening sockets, causing re-use failure on tomcat startup
# https://unix.stackexchange.com/questions/123413/close-all-file-descriptors-in-bash
for fd in $(ls /proc/$$/fd); do
    case "$fd" in
        0|1|2)
        ;;
    *)
        eval "exec $fd>&-"
        ;;
    esac
done

if test "$1" != setsid; then
    date; echo "Invoked with pid $1, restarting ourselves"
    setsid $0 setsid $1 &
    exit 0
fi

`dirname $0`/shutdown.sh
date; echo "Shutdown called"
java="$2"
date; echo "Waiting for $java to die"
laps=200
while test -e /proc/$java; do
    sleep 0.1
    laps=$((laps-1))
    # if shutdown failed to stop the server,
    # we must kill it, but this may leave
    # open ports, so we delay ourselve for
    # some time.
    test $laps -eq 0 && {
        date; echo "Waited too long, killing"
        kill -9 $java
        sleep 120
        break;
    }
done

date; echo "About to restart the server"

# You can send an email, or some other notification here
# Mail -s "Tomcat restarted due to OOM" << _EOF_
# Tomcat PID $java has been restarted due to OOM
# _EOF_

# sleeping for a while for process to die for sure
sleep 5

# this script is expected to be at bin directory
# of the corresponding tomcat. If not, change the path

date; echo "Calling startup.."

`dirname $0`/startup.sh
) >> /tmp/restart.log 2>&1