JRockit Mission Control vs Wily

We’ve been using CA Wily Introscope to monitor one of our production systems for a couple of years. It has been very useful in providing a detailed insight into what is going on with the Java tier including the ability to look back in time and do root cause analysis after a problem has happened.

In particular, we use Wily to monitor the throughput and response time of our ‘front ends’ (servlets, EJBs etc), the ‘back end’ (JDBC calls) as well as keeping an eye on key JMX metrics such as the number of messages in JMS queues and the behaviour of the heap and garbage collector. All in all, it’s a very useful tool that I wouldn’t like to be without.



Another customer that I’ve been working with more recently has suggested either Wily or Oracle JRockit Mission Control (JRMC) as monitoring solutions. I’ve mostly worked with the Sun JVM until now so I didn’t know much about JRMC. I decided to try to figure out how it stacked up against Wily.


This post is about my first impressions of JRMC and its suitability for my own needs. I wouldn’t claim that it’s a comprehensive comparison, so please forgive any errors or omissions.

Pros

• It’s much easier to get a copy of JRMC than Wily
• No interceptor setup needed
• Easier to use for a 'quick look'
• Probably a better tool for general profiling when you’re not sure where a performance issue might be
• I like the ‘wait events’ profiling – this seems rather similar to what an Oracle AWR report shows in the database… it remains to be seen whether it proves as useful in the Java tier.
• Looks like it has some useful features for diagnosing memory leaks, but I’ll reserve judgement until I’ve used them on a real life problem.
• Can trigger thread/heap dumps etc from the same console
• Probably better targeted garbage collection visibility for JRockit

Cons

• Many features only work with the JRockit 1.6 VM
• It doesn’t seem to support the notion of a centralized permanent data repository
• Without a data repository, I suspect that any long term trend reporting will be very difficult
• It doesn’t seem to have the capability to build ‘traffic light’ dashboards and drill down from these to the detailed monitoring data

In summary, I think that both Wily and JRMC are useful tools. JRMC probably scores more highly on more detailed JVM analysis and ease of getting started. Wily does a better job of monitoring a production system and historical trend reporting.

My first choice would be to have both tools available. If I had to choose between them I’d probably stick with Wily for production system monitoring and possibly go for JRMC for monitoring performance tests.