Custom Service name provider for Java

[mortada87]

Hello,
I need to be able to dynamically set the service name for my Opentelemetry java agent, so that it takes the context path of the webapp, knowing that , multiple wars run on the same tomcat instance.
thanks for your help and for the great job done on this subject.
Hamid

[trask]

hi @mortada87 this may be what you are looking for: open-telemetry/opentelemetry-java-contrib#562

cc @breedx-splk

[mortada87]

You can simply load the jar with that lib as a javaagent extension

Thanks a lot

[trask]

i cannot write something myself to do that?

it's not straight forward, but it is possible, at a high level:

• write a SpanExporter wrapper, and "mutate" span resources based on their http.target
• in order to make this work for child spans also, you would need to pass the http.target down from the parent spans to the child spans so that it is available in your SpanExporter wrapper

[mortada87]

Hello Trask, thanks a lot, it would be something like this?

public void export(Collection<SpanData> spanDataCollection) { spanDataCollection.stream().map(spanData -> spanData.getResource().merge(Resource.create(Attributes.of(ResourceAttributes.SERVICE_NAME,TracerHelper.getApplicationame())))); }

Thanks,

Hamid

[trask]

SpanData is immutable, so you'll probably need to put the merged resource into a "new" SpanData, e.g. using https://github.com/open-telemetry/opentelemetry-java/blob/main/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/data/DelegatingSpanData.java

[mortada87]

Thanks a lot for your help! Will give it a try.