Instrumenting a 3rd party app

[Andy Chambers]

Hi folks,

I'm still pretty new to metrics/monitoring and java so this might be a dumb question but is it possible to

instrument a 3rd party java app (e.g. zookeeper) with any/all of the jvm metrics sets without modifying

the code of the 3rd party app? Seems like jmx *might* make this possible but I'm aware of the

recommendation about not using jmx.

I get that apps should push not poll their metrics but is the case described above a good use-case for

poll? If not, what would you do instead to monitor apps for which you can't modify the code?

Cheers,

Andy

[Vladimir Kroz]

Andy, 

Metrics library is intended to help developers in producing metrics in application they develop. There is no use for instrumenting 3rd party application. Given that said however, you're looking to the right direction -- there are number of standard or semi-standard ways to instrument 3rd party apps. As for Zookeeper specifically there are number of ways available to instrument and monitor:

1) JMX (as you correctly noticed)

2) 4-letter commands

3) Zookeeper log files

4) Numerous tools which based on above-mentioned methods.

Best,

Vlad