Add jaeger remote sampler

[pavolloffay]

Is your feature request related to a problem? Please describe.

I want to use Jaeger remote sampler https://github.com/open-telemetry/opentelemetry-java/tree/main/sdk-extensions/jaeger-remote-sampler with Javaagent

Describe the solution you'd like

Make https://github.com/open-telemetry/opentelemetry-java/tree/main/sdk-extensions/jaeger-remote-sampler available in the javaagent distribution.

Describe alternatives you've considered

Build a custom javaagent.

Additional context

Jaeger remote sampler in the spec: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/sdk-environment-variables.md

[mateuszrzeszutek]

You don't really need to build a custom javaagent, you can use the sampler as an extension.

[trask]

You don't really need to build a custom javaagent, you can use the sampler as an extension.

👍

it would still be nice to add this to the javaagent distribution since there's already spec support for OTEL_TRACES_SAMPLER=jaeger_remote

@pavolloffay is this the same as #1953?

[pavolloffay]

It seems related to #1953. I would say the #1953 is not correctly defined as the sampling strategies are not pulled by the exporter.

[pavolloffay]

I have started looking at this.

@anuraaga is my understanding correct that the Jaeger remote sampler will require some work to make this work in the auto-instrumentation? The root cause is open-telemetry/opentelemetry-specification#1996?

Or could we use one of grpc-okhttp, grpc-netty, or grpc-netty-shaded for the remote sampler?

I am getting the following error.

[otel.javaagent 2021-12-15 16:09:07:268 +0100] [main] INFO io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 1.10.0-SNAPSHOT
ERROR io.opentelemetry.javaagent.OpenTelemetryAgent
io.grpc.ManagedChannelProvider$ProviderNotFoundException: No functional channel service provider found. Try adding a dependency on the grpc-okhttp, grpc-netty, or grpc-netty-shaded artifact
	at io.grpc.ManagedChannelProvider.provider(ManagedChannelProvider.java:43)
	at io.grpc.ManagedChannelBuilder.forTarget(ManagedChannelBuilder.java:76)
	at io.opentelemetry.exporter.otlp.internal.grpc.DefaultGrpcExporterBuilder.build(DefaultGrpcExporterBuilder.java:131)
	at io.opentelemetry.exporter.jaeger.JaegerGrpcSpanExporterBuilder.build(JaegerGrpcSpanExporterBuilder.java:92)
	at io.opentelemetry.sdk.autoconfigure.SpanExporterConfiguration.configureJaeger(SpanExporterConfiguration.java:186)
	at io.opentelemetry.sdk.autoconfigure.SpanExporterConfiguration.configureExporter(SpanExporterConfiguration.java:104)
	at io.opentelemetry.sdk.autoconfigure.SpanExporterConfiguration.lambda$configureSpanExporters$1(SpanExporterConfiguration.java:94)
	at java.base/java.util.stream.Collectors.lambda$uniqKeysMapAccumulator$1(Collectors.java:178)
	at java.base/java.util.stream.ReduceOps$3ReducingSink.accept(ReduceOps.java:169)
	at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1603)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578)
	at io.opentelemetry.sdk.autoconfigure.SpanExporterConfiguration.configureSpanExporters(SpanExporterConfiguration.java:89)
	at io.opentelemetry.sdk.autoconfigure.TracerProviderConfiguration.configureTracerProvider(TracerProviderConfiguration.java:61)
	at io.opentelemetry.sdk.autoconfigure.OpenTelemetrySdkAutoConfiguration.newOpenTelemetrySdk(OpenTelemetrySdkAutoConfiguration.java:104)
	at io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdkBuilder.build(AutoConfiguredOpenTelemetrySdkBuilder.java:177)
	at io.opentelemetry.javaagent.tooling.OpenTelemetryInstaller.installOpenTelemetrySdk(OpenTelemetryInstaller.java:42)
	at io.opentelemetry.javaagent.tooling.AgentInstaller.installBytebuddyAgent(AgentInstaller.java:125)
	at io.opentelemetry.javaagent.tooling.AgentInstaller.installBytebuddyAgent(AgentInstaller.java:96)
	at io.opentelemetry.javaagent.tooling.AgentStarterImpl.start(AgentStarterImpl.java:65)
	at io.opentelemetry.javaagent.bootstrap.AgentInitializer.initialize(AgentInitializer.java:37)
	at io.opentelemetry.javaagent.OpenTelemetryAgent.startAgent(OpenTelemetryAgent.java:55)
	at io.opentelemetry.javaagent.OpenTelemetryAgent.premain(OpenTelemetryAgent.java:44)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:513)
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:525)
^C% 

[trask]

oh ya, this is because we don't use grpc or protobuf dependencies anymore. all the standard otel exporters (including the jaeger exporter) now hand marshal the protobuf data and send it directly using okhttp. check out for example open-telemetry/opentelemetry-java#3800.

not including grpc/netty/protobuf dependencies saved us a few MB in the javaagent jar, so I don't think we would want to bring those dependencies back just to support jaeger remote sampler.

probably will need to update the jaeger remote sampler to use similar "grpc lite" mechanism first

[pavolloffay]

thanks Trask, I will take a look at it in the otel-java repo.