There are 2 solutions you can use to monitor a running XWiki instance:

• Use a Profiler. This has the advantage of providing advanced information but has the drawback of being resource intensive and thus slowing the XWiki instance. It also requires a special startupscript
• Starting with XWiki Enterprise 2.4M2 we've now started using the JMX Technology to provide runtime monitoring of XWiki instances. The following features are currently available:
  • Monitor the Velocity macro caches
  • Monitor the caches XWiki is using to cache Document data, Users & Groups data and more

JMX Console

Since JMX is a standard you can use any JMX-compatible monitoring console (most application servers provide a web-based JMX console). There's also such a console bundled by default in the Java Runtime you're using. To start it, simply execute the jconsole executable.

Example of JConsole showing the Velocity Cache monitoring: