Sometimes my tomcat server auto shutdown due to some memory issue, so I want to use the below script to check whether tomcat is running:
checkTomcatRunning.sh
TOMCAT_PID=$(ps -ef | awk '/[t]omcat/{print $2}')
echo TOMCAT PROCESSID $TOMCAT_PID
if [ -z "$TOMCAT_PID" ]
then
echo "TOMCAT NOT RUNNING"
sudo /opt/tomcat/bin/startup.sh
else
echo "TOMCAT RUNNING"
fi
Below is the crontab which output log to /opt/tomcat/logs/checkTomcatRunning.log
crontab -l
*/1 * * * * /opt/tomcat/webapps/checkTomcatRunning.sh >>/opt/tomcat/logs/checkTomcatRunning.log 2>&1
in /opt/tomcat/logs/checkTomcatRunning.log, I can see 4 PID printed
cat /opt/tomcat/logs/checkTomcatRunning.log
TOMCAT PROCESSID 53585 53916 53917 53918
TOMCAT RUNNING
If run ps -ef | awk '/[t]omcat/{print $2}' from linux command line, there is only 1 PID 53585
ps -ef | awk '/[t]omcat/{print $2}'
53585
And I can only find 53585 in the running process, but not 53916 53917 53918.
ps -p 53585 53916 53917 53918
PID TTY STAT TIME COMMAND
53585 pts/0 Sl 0:50 /usr/bin/java -Djava.util.logging.config.file=/opt/tomcat/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pk
Can anyone help to advise why there are 4 (but not 1) PIDs printed in checkTomcatRunning.log?
