Modifying startup script for tomcat deployment using Maven

Question

I am using a profiling tool, which gets loaded as and when I startup Tomcat with the application war file placed in the webapps directory. So once I run startup, my classes get instrumented and everything works fine.

But for this, I am taking the war file generated as part of maven install ( which downloads tomcat and deploys the war file in it) , and placing it in another tomcat which I have downloaded manually. Then I need to do some editing in the catalin.bat file, to set the JAVA_OPTS property to the javaagent so that it gets started on startup.

What I would like to do is, setup the tool and integrate it with maven such that on a clean and install, the classes gets instrumented and the profiling tool starts running. I believe we can do some configuration changes in pom.xml to achieve this? Any help in this regard would be greatly appreciated! Thanks

Answer 1

This is only part of what you need, but you should configure your tomcat in a different way - maybe this eases your task sufficiently that you'll be able to solve the rest yourself:

You don't need to update catalina.bat - instead create a file named setenv.bat in the same directory: It's not included in tomcat, but if it's there, it will be taken into account during startup/shutdown of tomcat.

Speaking about startup/shutdown: The JAVA_OPTS that you set in this file will be used for startup as well as shutdown (there's a java process started when tomcat shall shut down, running for a brief time). If you have massive memory requirements, allocate JMX ports etc, these will apply for both processes, thus may be conflicting. You rather want to set CATALINA_OPTS - this is just used for starting tomcat, not for shutting it down.

So, the typical content for setenv.bat is

SET CATALINA_OPTS="-DyourSettings -DwhateverYouLike"

And, by the way, the same works for setenv.sh on other platforms