Redirecting otel javaagent logs to instrumented application

[masonedmison]

I'm trying to determine why some of my configured JMX metrics are not being exported. To debug this, I'm trying to set up the javaagent to redirect its logs to the instrumented application's logs.

So far, I've set the following environment variables:

OTEL_JAVAAGENT_DEBUG: "true"
OTEL_JAVAAGENT_LOGGING: application

Also, I've added this to the instrumented application's logback.yaml file:

<logger name="io.opentelemetry.instrumentation.jmx" level="ALL" />

When greping the logs, I see no log entries including jmx.

For additional context, I'm starting my application referencing user-defined rules like:

-Dotel.jmx.config=/opt/docker/opentelemetry/jmx/cassandra.yml

where cassandra.yml is:

rules:
  - bean: com.datastax.oss.driver:name=cassandra.s0.bytes-sent,type=meters
    mapping:
      Count:
        metric: my.own.cassandra.sent.count
        type: counter
      MeanRate:
        metric: my.own.cassandra.sent.mean
        type: gauge
  - bean: java.lang:type=Threading
    mapping:
      ThreadCount:
        metric: my.own.jvm.thread.count
        type: updowncounter
        desc: The current number of threads
        unit: "1"

The specific issue I'm encountering is that the my.own.jvm.thread.count is exported, but the my.own.cassandra.* metrics are not.

I've verified that the Cassandra bean exists--it does, see screenshot

Given this context, my thought is that I should enable logging to see if the Cassandra bean isn't able to be found (e.g., in BeanFinder). Though, I'm certainly open to any ideas or attention anyone may be able to share to help me resolve this issue.

Thanks in advance!

[masonedmison]

From what I can tell, unit is actually required--when I added unit to the example above, this metric is exported. Note that the document lists this field as optional 🤔

[SylvainJuge]

Hi !

Thanks for reporting this issue, I have opened #13796 to fix it. With that change the metric should have been reported with an empty string as metric, however I don't know if the backend you use allows that.