Fix config for zookeeper standalone

[rafitadiaz]

The metrics from the JMX exporter have this format:

org.apache.ZooKeeperService<name0=StandaloneServer_port-1><>MinRequestLatency)

So the regexp needs a - after port.

[brian-brazil]

Hmm, did this change at some point? It'd seem odd that you'd be the first person to notice such an obvious breakage.

[rafitadiaz]

Not sure, I just did this setup in my staging like 3 weeks ago and I found this.
In my case the versions that I'm using are:

zookeeper-3.4.6-1.el7.x86_64
jmx_prometheus_javaagent-0.12.0.jar

And debugging the Mbeans with jconsole I found a tree like this

> org.apache.ZooKeeperService
  > StandaloneServer_port-1
    > ....

I'm not familiar with Mbeans or Java processes so maybe it's a misconfiguration in the zookeeper server for Centos7 (I'm using the RPM package with the default conf)

[brian-brazil]

No, this shouldn't be affected by configuration. Hmm could it be that the port in this case is -1, that is negative?

[rafitadiaz]

Oh, I understood that the port was 1... like port-(\\d)
I don't think that I've never seen a negative port before. 🤔 and it sounds like a really weird default value but it could be.

If for another people is working without the - we also can go for a more generic implementation for the regexp with:

    org.apache.ZooKeeperService<name0=StandaloneServer_port-*(\\d*)><>AvgRequestLatency)

That should work for metrics with and without -

[brian-brazil]

If it's part of the number we should capture it. We need to know where this is coming from though, as this is not what is documented.