A lot of server software runs on Java, but the different Java processes are listed as simply Java via commands like top or ps -ef. One feature of the Stackify agent is tracking the running processes on a server. I needed a way to identify what each Java process really was in a fairly simple and concise way, but there isn’t a clear winner in the output of the top or ps commands.
Running ps -ef | grep java will output something nasty, similar to what follows. You can likely figure out what the Java process is actually running from the args — the example below obviously being tomcat — however, it’s not the most readable and doesn’t give a clear and concise value to display to a user in the Stackify web site. The user of the process below also indicates that it is running tomcat, but that won’t be the case for all Java processes.
tomcat7 41298 1 5 18:05 ? 00:00:03 /usr/lib/jvm/default-java/bin/java -Djava.util.logging.config.file=/var/lib/tomcat7/conf/logging.properties -Djava.awt.headless=true -Xmx128m -XX:+UseConcMarkSweepGC -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/usr/share/tomcat7/endorsed -classpath /usr/share/tomcat7/bin/bootstrap.jar:/usr/share/tomcat7/bin/tomcat-juli.jar -Dcatalina.base=/var/lib/tomcat7 -Dcatalina.home=/usr/share/tomcat7 -Djava.io.tmpdir=/tmp/tomcat7-tomcat7-tmp org.apache.catalina.startup.Bootstrap start
I decided it might work to differentiate the Java processes by working directory, but I wasn’t sure if there was a good way to find the working directory. Through some Google searches I discovered the pwdx command. The pwdx command takes a list of pids as parameters and outputs a row with the pid and the working directory for each pid. The working directory doesn’t work for all situations, but I’ve found it generally gives a concise way of determining what a Java process is actually running. I’m certainly open to suggestions if anyone has a better idea.
Running the pwdx command for the output above — sudo pwdx 41298 — leads to the following output. By combining this with the process name I can give the Java processes a more informative name when displayed in the Stackify website. This Java process would be displayed as Java (/var/lib/tomcat7).
41298: /var/lib/tomcat7