Histogram startTimer() fails when applying labelNames

[acarlstein]

#How you doing?
I apologize to bother you but I think I may have encounter a possible bug.
I tried to find any solution or explanation to the problem unsuccessfully, else I would not be bothering you.

In Java or Groovy, this works:

Histogram requestLatency = Histogram.build().name("xrequests_latency_seconds").help("Request latency in seconds.").register();
Histogram.Timer requestTimer = requestLatency.startTimer();
try {
	TimeUnit.SECONDS.sleep(1);
} finally {
	requestTimer.observeDuration();
}

While this fails:

Histogram requestLatency = Histogram.build().name("xrequests_latency_seconds").help("Request latency in seconds.").labelNames("Feeling").register();
Histogram.Child histogramChild = requestLatency.labels("sleepy");									
Histogram.Timer requestTimer = requestLatency.startTimer();
try {
	TimeUnit.SECONDS.sleep(1);
} finally {
	requestTimer.observeDuration();
}

Producing this Exception:

java.lang.NullPointerException at io.prometheus.client.Histogram.startTimer(Histogram.java:282)

I have apply similar approach using labels with Counter and Gauge, no problems there.

Note: I am using io.prometheus:simpleclient_common:0.0.20 and io.prometheus:simpleclient:0.0.26

[brian-brazil]

This is correct, for a labelled metric you must specify the labels.

It makes more sense to ask questions like this on the prometheus-users mailing list rather than in a GitHub issue. On the mailing list, more people are available to potentially respond to your question, and the whole community can benefit from the answers provided.

[acarlstein]

@brian-brazil,

Since English is my second language, I may have explained myself wrong. For that I apologize.

Histogram is failing when I am applying the labels.
The second code example I provided ends in NullPointerException.
Is this supposed to happen? If so, why?

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.