Micrometer: Kafka consumer Metrics values are always NaN

[thirunar]

We have upgraded micrometer version to 1.1.0 to get the KafkaConsumerMetrics in our spring boot application v2.1.0.

But apparently, all the kafka consumer metrics are being collected and only has NaN as its value. Few people have reported the issue in StackOverFlow.

You can refer to simple project created by @j-tim. I also have the same issue with my metrics.

What could be the reason? Could you please help us with the issue?
Thank you!!

[jkschneider]

Thanks, will look into it and release a patch version.

[thirunar]

Thank you for the response. Any plan for patch release date?

[rikitikitaco]

I believe this is due to the MBeans not being found as the clientId is different. Something adds a -0 to the end.

[jkschneider]

Related, I think, to #878

[hgnoyke]

We are seeing a similar problem when having a consumer linked to a topic where no messages are being recieved (we have a topic on which we send time-travel-events for testing to different apps and sometimes do not use this feature ;-) ).

Here is one of the error messages:
failed to send metrics to influx: {"error":"partial write: unable to parse 'kafka_consumer_fetch_latency_max,client_id=consumer-1,[our_custom_tags_left_out],metric_type=gauge value=-∞ 1541775345266': invalid number

Guess we are getting "negative infinity" because no message has been processed yet or this value has to be given to InfluxDB in a different way?
For the time being we have switched off

Don't know whether this is related to this "NaN" issue or should be handled in a different issue.
Thanks for looking into this!