I had a good talk with Kees Jan Koster and Ulf Dittmer the other day. Kees is preaching the virtues of his java-monitor tool, a neat little application that does just what it promises: it monitors your JVMs.
Kees got the idea after playing with JMX and discovering all of the neat stuff that you can find out about the JVM, including information about memory usage, thread allocation and heap usage. He put together a little application that garners these statistics, graphs it over time, and allows you to see visually what your JVM is up to.
I played with it myself, putting it up against a WebSphere Portal 8 installation. The installation was straight forward, the monitoring was pretty immediate, and you could easily configure alerts to be sent via SMS or email if the java-monitor site thinks your JVM is being unresponsive. An administrator can't complain about that type of feedback, that's for sure.
By the way, this week in the JavaRanch forums they're actually doing a bit of a promotion, giving away a license for some lucky greenhorn that asks a question or two about the product. The product itself is licensed under a freemium model where you can get the basic functionality I mentioned above for free, while extra functionality comes at a nominal price. But if you participate in the CodeRanch forums this week, you might win a license, which provides the best of both worlds.
For more information check out java-monitor.com