parfait-agent initializes before main app so JMX MBeans do not exist

[rwallinterset]

I have been trying to figure out how to use parfait and I thought I had it all figured out but I can't get my custom jmx mbeans to be registered. I am currently running parfait using the javaagent argument when calling my app. After lots of messing around I think the issue is that parfait is being loaded before my app initializes so the JMX mbeans do not exist at the time time parfait is initialized. What am I doing wrong?

I also tried to figure out how the JMXconnector works as I thought that might be a better way to go but I can't figure out how to configure the proxy.xml to point it at a specific java app.

Any help would be appreciated.

[rwallinterset]

Ok so I confirmed that was the issue. I created a new thread class and if I spin a thread with a sleep in it which then executes the ParfaitAgent premain method all works fine.

[tallpsmith]

@natoscott will have to comment directly here on the current state, but I believe right now parfait-agent will only export some known JVM metrics, there's not yet a mechanism to export custom (application-specific) metrics as yet (though that is definitely the plan).

Part of the Parfait lifecycle requires a 'quiet' period for new metrics to appear - it waits up to 5 seconds after the last detected metric has been registered before (re)starting the export. This prevents a large application starting up, registering a lot from tripping a blitz of registrations to PCP. Once the application has quieted down, Parfait will begin exporting to PCP.

Eventually your own JMX/custom metrics will be registered by a mechanism like an XML config.

You might also want to look at the Parfait-DropWizard integration (part of this module). If you are using DropWizard metrics in the application, it's pretty easy to have these exported to PCP.

[natoscott]

@tallpsmith that's correct - addition of user-defined metrics, as described, is WIP (as is exposing the Parfait delayed initialization concept). With the earlier reference to proxy.xml, that's just a placeholder at this stage - also WIP.

[natoscott]

Just a bit more followup here - parfait-agent has always used the DynamicMonitoringView Parfait class, which performs the delayed-initialisation-if-needed @tallpsmith referred to above (re 'quiet' period). I've just added some code to allow the application startup time to be set to something different to the default 5 seconds if need be. I'll be looking into the proxying mode shortly too.