Jmx unit semconv alignment - Tomcat

[robsunday]

Changes:

1. Metric names made semconv aligned
2. Attribute names made semconv aligned
3. Metrics descriptions format standardized
4. tomcat.yaml moved from agent to library folder to make it reusable in all library dependants
5. Tomcat JMX metrics Integration test implemented. It utilize assertions and target system integration test framework ported by @SylvainJuge from opentelemetry-java-contrib

[robsunday]

[for reviewer] Tomcat metrics definition is tested in a much better way in TomcatIntegrationTest.java

[SylvainJuge]

By "much better way" here it means being tested against a real tomcat instance rather than trying to parse the yaml file to see if there are any errors.

[robsunday]

Moreover, it can now be easily tested with multiple tomcat versions

[SylvainJuge]

@robsunday #13597 has been merged, so you can update with current state of main to make diff simpler.

[SylvainJuge]

I think that processingTime and maxTime mbean attributes are related, so we should probably make sure their name reflect that, for example:

• tomcat.request.max.time for maxTime + tomcat.request.total.time for processingTime
• having the total or max not at the end of the metric name helps to avoid the "do not use total" rule in semconv
• alternatively, we could argue that the "do not use total" rule in semconv refers only to the _total and not total suffix and then use tomcat.request.time.max and tomcat.request.time.total but this might be harder to make people agree on this.

[robsunday]

I mapped maxTime to tomcat.request.duration.max to make it similar to one of http semconv metrics
I'd keep this name, and i could then map processingTime to tomcat.request.duration.total
I think .total suffix is fine because semconv rule you mentioned is talking specifically about _total suffix, not .total

[SylvainJuge]

It would be worth to ask and double-check in the SIG meeting if .total could be fine as suffix, because if it does then it sounds like a good strategy that would be consistent with other "pre-aggregated metrics", for example it's easy to add an tomcat.request.duration.max

[SylvainJuge]

It would be worth to ask and double-check in the SIG meeting if .total could be fine as suffix, because if it does then it sounds like a good strategy that would be consistent with other "pre-aggregated metrics", for example it's easy to add an tomcat.request.duration.max

[SylvainJuge]

For the processor name, I think we could maybe use tomcat.request.processor.name as it allows to reuse the tomcat.request namespace, and as I understand defining more namespaces than strictly needed in semconv and avoiding _ is the current strategy, even if we don't have anything extra to provide in the tomcat.request.processor name yet.