Count cores allocated to a Tomcat, TomEE or ActiveMQ instance. Steps:

• Download the cores.jar file.
• Run from inside the vm or machine where the Tomcat, TomEE, or ActiveMQ process is running.
• Repeat for all instances of Tomcat, TomEE, or ActiveMQ.

Run in Linux/Windows via:

java -jar cores.jar 

Be sure to run cores.jar using the same Java version as your Tomcat, TomEE or ActiveMQ instance.

Alternatively, you can deploy a JSP on each Tomcat, TomEE or ActiveMQ instance. Steps:

• Download the cores.jsp file.
• Add this to the webapps/ROOT folder (assuming the ROOT application is deployed) or another application on Tomcat/TomEE
• Add this to the webapps/admin folder on ActiveMQ
• Access the cores.jsp page via your server's web UI, for example http://your-server:8080/cores.jsp on Tomcat/TomEE, or http://your-server:8161/admin/cores.jsp on ActiveMQ.

If you prefer, you can deploy the cores.war in Tomcat or TomEE's webapps folder, and the application should be accessible via the server's web connector, for example: http://localhost:8080/cores/