Problem with JMX query of Coherence node MBeans visible in JConsole

Question

I'm using JMX to build a custom tool for monitoring remote Coherence clusters at work. I'm able to connect just fine and query MBeans directly, and I've acquired nearly all the information I need. However, I've run into a snag when trying to query MBeans for specific caches within a cluster, which is where I can find stats about total number of gets/puts, average time for each, etc. The MBeans I'm trying to access programatically are visible when I connect to the remote process using JConsole, and have names like this: ``` Coherence:type=Cache,service=SequenceQueue,name=SEQ%GENERATOR,nodeId=1,tier=back ``` It would make it more flexible if I can dynamically grab all `type=Cache` MBeans for a particular node ID without specifying all the caches. I'm trying to query them like this: ``` QueryExp specifiedNodeId = Query.eq(Query.attr("nodeId"), Query.value(nodeId)); QueryExp typeIsCache = Query.eq(Query.attr("type"), Query.value("Cache")); QueryExp cacheNodes = Query.and(specifiedNodeId,…

Accepted Answer

Just wanted to post my solution for posterity...

I have been able to successfully retrieve the set of MBeans matching the specified characteristics through a simpler (yet stranger) approach. I still don't know why the `QueryExp` approach doesn't work, but here's what does work (replaces the last line of code in my question):

```
Set<ObjectName> cacheMBeans = mBeanServer.queryNames(new ObjectName("Coherence:type=Cache,nodeId="+nodeId+",*"), null);
```

It also works when adding a fragment `service=SequenceQueue` in the ObjectName constructor string to filter by Coherence service (cache) name.

As long as it works somehow, it's enough for me to get my job done, but this seems like a glaring flaw in the JMX implementation. And don't get me started on the process for creating a working JMXServiceURL using JMX and RMI...

Problem with JMX query of Coherence node MBeans visible in JConsole

Solution

Problem