It’s critical for us to configure all correct parameters while running your application in Production environment or even in development env. While GUI makes it very user-friendly and easy to set up the right values in the right fields, it's useful to know how to do the same programmatically/without the "Configure Tomcat" utility.


One way, if you're using Tomcat as a Windows service, you can adjust the JVM options by going to the bin dir and running:

tomcat8 //US//MYSERVICENAME"C:\Program Files\example" 

Turn the service off before you do this and restart it when you finish.


cd $CATALINA_HOME .\bin\service.bat install tomcat .\bin\tomcat8.exe //US//tomcat8 --JvmMs=512 --JvmMx=1024 --JvmSs=1024


Setting the --JvmXX parameters may not be enough. You may also need to specify the JVM memory values explicitly. From the command line it may look like this:

bin\tomcat8w.exe //US//tomcat8 --JavaOptions=-Xmx=1024;-Xms=512;..


Be careful not to override the other JavaOptions.


But the best and recommended way is to use (Linux/Windows respectively). It isn't in the as-downloaded Tomcat. But if you look in, there's a check for a file called setenv. If it's there, it's run. That's where you set JAVA_OPTS, CATALINA_OPTS, etc. We use it to set JAVA_HOME, JAVA_OPTS, CATALINA_OPTS and JPDA_ADDR. Putting all your environment variables into this file is ideal because then you don't have to change the stock startup scripts.



Then when monitoring the log we can see the parameters taken: