Distributed tracing for LEAF data services

Data Services
1

:leaves: LEAF version: 3.12.x

:jigsaw: LEAF component(s): Data service

Issue/Question: I am trying to add distributed tracing to a LEAF-generated data service and have 2 questions.

  1. The LEAF docs mention support for OpenTracing implementations. OpenTracing was deprecated in 2022 and replaced with OpenTelemetry. Does LEAF have support for OpenTelemetry (with or without installed bridges) - and if not are there any first-class alternatives?
  2. The LEAF JavaDocs have a TracerUtils class - I am not able to import it even after adding the referenced gradle dependencies in the docs. Is there another dependency to add?

Thank you in advance for any assistance.

2

LEAF does still use the OpenTracing Tracer interfaces, but the implementation LEAF provides by default is the OpenTelemetry one.

In the project I work on now, I have:

implementation "com.leidos.leaf:platform-services-open-tracing"

in my build.gradle. And the version is managed by the LEAF Gradle plugin. Specifically I’m using 3.16.0 per this:

apply plugin: "com.leidos.leaf.base"

leaf {
    frameworkVersion = "3.16.3"
    platformVersion = "3.16.0"
}

That should transitively bring in the framework-services-core package, I would think, but if not make sure you also have it, or something that brings it in (most every framework-services-x` package brings it in transitively).

If you can paste in your build.gradle that might help with diagnosing why the packages aren’t available.

3

Hi @mark.a.alvaro,

Thanks for your quick response. That is good to know about the tracing implementation. Re: TracerUtils class. Here are the LEAF plugins/dependencies in my build.gradle. I can access all other tracing related code (e.g TracerHook, DataChangeEventTracerHook) - just not the utils class.

plugins {
    id "com.leidos.leaf.base" version "3.12.0" apply false
}

...

subprojects {
   apply plugin: "com.leidos.leaf.base"

   leaf {
         frameworkVersion = "3.12.1"
         platformVersion = "3.12.1"
   }

   dependencies {
        api "com.leidos.leaf:framework-services-rest-easy" 
        api "com.leidos.leaf:framework-services-rest"
        api "com.leidos.leaf:framework-services-metrics"
        api "com.leidos.leaf:framework-services-prometheus"
        api "com.leidos.leaf:framework-services-jetty"
        api "com.leidos.leaf:framework-services-mongo"
        api "com.leidos.leaf:framework-services-kafka"
        api "com.leidos.leaf:platform-services-core"
        api "com.leidos.leaf:platform-services-message-handling"
        implementation "com.leidos.leaf:platform-services-open-tracing"
        implementation "com.leidos.leaf:platform-services-service-discovery"
   }
}
4

Ah sorry should have paid a bit more attention to the file name. TracerUtils is a test util in LEAF that’s not published/meant for production use. The classes you want to use are below:

// Make tracer and register globally.
OpenTracingHandler openTracingHandler = OpenTracingHandler.newBuilder()
        .withServiceName("MyApplication")
        .build();
GlobalTracer.registerIfAbsent(openTracingHandler::getTracer);

// Make TracerHook and apply to IDataService
// Note you can apply to other hookable LEAF services too
// (e.g. IEventService, IFileService)!
TracerHook tracerHook = TracerHook.newBuilder()
        .withShouldHook(method -> !method.getIdentifier()
                .equals(MetadataServiceExtensible.LOAD_BEAN_METADATA_BY_EDITIONS))
        .build();
this.dataService.addOutermostHook(IDataService.SERVICE_PRED, tracerHook);
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