Enabling the quarkus.micrometer.binder.kafka.enabled property

[ShubhamRwt]

Hello,

I am working on moving the Strimzi Kafka bridge project with @ppatierno to use Quarkus and the HTTP REST part is already implemented using RESTeasy Reactive.
I am currently trying to add the metrics to bridge using the quarkus micrometer library. I was able to get the metrics which are there by default on http://localhost:8080/q/metrics. I saw that using the quarkus.micrometer.binder.kafka.enabled we can enable the Kafka related metrics but I am not able to see any metrics related to Kafka after setting this property to true. I also fulfil the conditions mentioned in the docs but still no good. Can you help me figure out where I am going wrong or why it is not working?

[quarkus-bot[bot]]

/cc @alesj (kafka), @brunobat (micrometer), @cescoffier (kafka), @ebullient (micrometer), @ozangunalp (kafka)

[ppatierno]

Thanks @ShubhamRwt for opening this!
Just to add that we are not using Kafka through the SmallRye dependency but directly the Kafka Java client through:

<dependency>
      <groupId>org.apache.kafka</groupId>
      <artifactId>kafka-clients</artifactId>
      <version>${kafka.version}</version>
</dependency>

it should fulfil the condition mentioned by the doc about Kafka Consumer or Producer interface is on the classpath

[brunobat]

That's correct.
Also, it applies only to kafka-clients, not kafka-streams. See: https://github.com/quarkusio/quarkus/blob/main/extensions/micrometer/runtime/src/main/java/io/quarkus/micrometer/runtime/binder/kafka/KafkaEventObserver.java#L21

[ShubhamRwt]

But we are still not getting any metrics related to kafka. Even when the conditions are fulfilled :(

[alesj]

@ShubhamRwt can you debug and see if this observer kicks-in?

[ppatierno]

@alesj so we have this dependency for micrometer ...

<dependency>
     <groupId>io.quarkus</groupId>
     <artifactId>quarkus-micrometer-registry-prometheus</artifactId>
</dependency>

then quarkus.micrometer.binder.kafka.enabled=true in the application.properties.

When our code executes this kind of code for example (producer creation):

this.producer = new KafkaProducer<>(props, this.keySerializer, this.valueSerializer);

no breakpoint hits in the KafkaEventObserver.producerCreated

[alesj]

OK, I think we established what was the issue -- producers and consumers were not beans.
Let me know when the KafkaEvenObserver injection idea works for you, and we can close the issue.

[ppatierno]

Yes it worked. We inject the KafkaEvenObserver instance where we can and pass it down to the chain where we need it (which is not a bean).
Not sure we are going to use it just because our way to collect the metrics (via JMX collector) is anyway needed for getting others (not from Kafka client itself).
Anyway, I would say that this feature is really super useful :-)
Out of curiosity, how much is it customizable? i.e. adding a prefix to the metrics name, adding specific tags, filtering, and so on?

[alesj]

Out of curiosity, how much is it customizable? i.e. adding a prefix to the metrics name, adding specific tags, filtering, and so on?

This is out of Quarkus' "jurisdiction", as this is then Micrometer + Kafka code.

• see KafkaMetrics class in micrometer-core artifact

[alesj]

@ppatierno it takes Metrics from consumer/producer/admin ... and turns them into Micrometer metrics.
I guess if you can modify the metrics (before you pass them to KafkaEventObserver) on the consumer/producer/admin, it should reflect in the Micrometer metrics.

[ebullient]

Micrometer also has MeterFilter, which you can use to alter metric names and tags (though there are constraints on the information available if you want to add tags).

https://quarkus.io/guides/micrometer#using-meterfilter-to-configure-metrics

Remember that metrics are for use in aggregate as indicators, not for audit/debug purposes. ;)

[ppatierno]

Remember that metrics are for use in aggregate as indicators, not for audit/debug purposes. ;)

Wdym by this? We don't want to use metrics for audit/debug purposes.

[ebullient]

I've seen folks start putting things in tags that are too finely detailed... so, was just a reminder. ;)