Also catch ClassNotFoundException when trying to instantiate datadog.opentracing.jfr.openjdk.ScopeEventFactory.

[alacoste]

I am getting an uncaught exception that seems to have been forgotten in the anticipated catch block:

java.lang.ClassNotFoundException: datadog.opentracing.jfr.openjdk.ScopeEventFactory
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Class.java:340)
	at datadog.opentracing.DDTracer.createScopeEventFactory(DDTracer.java:560)
	at datadog.opentracing.DDTracer.access$000(DDTracer.java:55)
	at datadog.opentracing.DDTracer$DDTracerBuilder.config(DDTracer.java:121)
	at datadog.opentracing.DDTracer$DDTracerBuilder.withProperties(DDTracer.java:110)
	at ace.client.external.tracing.TracingClient$Companion.test(TracingClient.kt:71)
	at ace.ApplicationKt$main$4.invokeSuspend(Application.kt:210)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:56)
	at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:271)
	at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:79)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:54)
	at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
	at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:36)
	at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
	at ace.ApplicationKt.main(Application.kt:209)
	at ace.ApplicationKt.main(Application.kt)

[mar-kolya]

Hi @alacoste, thanks for PR.

Could you please clarify what kind of setup you have? Ideally would you be able to provide a simple reproducer that triggers the problem?

[alacoste]

Hi @alacoste, thanks for PR.

Could you please clarify what kind of setup you have? Ideally would you be able to provide a simple reproducer that triggers the problem?

Hi @mar-kolya, I'll try to make a small & simple reproducer, but here's our setup in the big lines:

• Kotlin project using gradle
• I was trying to use only the opentracing APIs and setup the DDTracer entirely from code (no java-agent, no config file).

build.gradle.kts:

implementation("com.datadoghq:dd-trace-ot:0.47.0")
implementation("io.opentracing:opentracing-api:0.33.0")

Sample code to construct the DDTracer:

val properties = Properties()
properties.setProperty("trace.enabled", "true")
properties.setProperty("service.name", "backend")
properties.setProperty("trace.agent.unix.domain.socket", "/.../my_socket")
val tracer: Tracer = DDTracer.builder()
    .withProperties(properties)
    .defaultSpanTags(mapOf("env" to "myEnv"))
    .build()

[mar-kolya]

@alacoste, thanks for the explanation for your setup.
This is indeed a bug and your suggested fix seems to be the right direction. Unfortunately it doesn't build - I'll create a separate PR to address this bug. Thank!

[alacoste]

@alacoste, thanks for the explanation for your setup.
This is indeed a bug and your suggested fix seems to be the right direction. Unfortunately it doesn't build - I'll create a separate PR to address this bug. Thank!

I'm guessing it's a missing import for ClassNotFoundException, I went a bit quickly doing it from the github UI directly.

Thanks for taking care of it

[mar-kolya]

@alacoste I've looked into this in a but more detail and it looks like ClassNotFoundException inherits from ReflectiveOperationException which is being caught and handled.

Could you please clarify: you see your app crash because of this - not just log an exception?
If it is crashing I guess we would need a reproducer because so far it is unclear.

[alacoste]

@alacoste I've looked into this in a but more detail and it looks like ClassNotFoundException inherits from ReflectiveOperationException which is being caught and handled.

Could you please clarify: you see your app crash because of this - not just log an exception?
If it is crashing I guess we would need a reproducer because so far it is unclear.

Tracing was working, but it would log an exception with stacktrace which seems like too much for the "problem" here (if this is an expected behavior in some cases).

I'm not sure whether the exception is caught at some higher level by my application code, or if this log was originating from datadog's code (and I switched to using my custom implementation of ScopeManager() so I don't have the issue anymore to check easily)

[mar-kolya]

Hmm. interesting, thanks for an update!

I think it would log this exception and stack trace if you have DEBUG logging for the tracer enabled. But that should not cause any real runtime problem - and normally this is not enabled.

[randomanderson]

This has been addressed in #1417