Enable replacing the ThreadPoolExecutor implementation

[ammachado]

for OpenTelemetry thread context propagation

[reta]

Thanks for the change, @ammachado . In CXF, we use bus extensions to provide alternative implementation (fe instrumented ones). For work queue, please use org.apache.cxf.workqueue.WorkQueueManager extension point where you could provide instrumented AutomaticWorkQueue implementation (over the default one, all classes are public). Thank you.

[ammachado]

Thanks for the change, @ammachado . In CXF, we use bus extensions to provide alternative implementation (fe instrumented ones). For work queue, please use org.apache.cxf.workqueue.WorkQueueManager extension point where you could provide instrumented AutomaticWorkQueue implementation (over the default one, all classes are public). Thank you.

Can you you provide more details where I can find this extension point?

[reta]

Can you you provide more details where I can find this extension point?

Sure, the default extensions come from [1] so you could have your own META-INF/cxf/bus-extensions.txt in application that overrides the default:

org.my.package.InstrumentedWorkQueueManagerImpl:org.apache.cxf.workqueue.WorkQueueManager:true

Upon initialization, the bus manager reads the extensions and initializes them. You could also do this programmatically:

bus.setExtension(org.apache.cxf.workqueue.WorkQueueManager.class, new org.my.package.InstrumentedWorkQueueManagerImpl());

[1] https://github.com/apache/cxf/blob/main/core/src/main/resources/META-INF/cxf/bus-extensions.txt

[ammachado]

I'm not sure I understood what you're saying... this PR already have a bus-extensions.txt providing a new WorkQueueManager. Should I remove this and move to my applications?

[reta]

Should I remove this and move to my applications?

Exactly, along with desired instrumentation, there are no changes required on CXF side.