AppD Java Agent for Web Apps - ClaasNotFound Error

[Akshay_Nimbal]

We've configured -Dappagent.start.timeout=30000 for the java agent for the webapps after we got the issue of Pods getting failed to start due to AppD taking lot of time initially which was delaying liveness probe in EKS. After adding timeout, as per the doc the AppD agent will start in parallel with the application startup reducing the overall startup time. Until few days ago, we started below issue in webapps running on Wildfly server where it is saying java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInterceptorDelegatorBoot and surprisingly it is giving this error when we remove the timeout configuration. Can anyone confirm if they came across this issue? 

9:17:46,228 INFO  [stdout] (AD Agent init) Agent will mark node historical at normal shutdown of JVM
09:17:50,323 INFO  [stdout] (AD Agent init) Registered app server agent with Node ID[455861] Component ID[6467] Application ID [553]
09:17:56,727 ERROR [stderr] (Reference Reaper #2) Exception in thread "Reference Reaper #2" java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInterceptorDelegatorBoot
09:17:56,729 ERROR [stderr] (Reference Reaper #2) 	at org.wildfly.common.ref.References$ReaperThread.run(References.java)
09:17:56,822 ERROR [stderr] (Reference Reaper #1) Exception in thread "Reference Reaper #3" Exception in thread "Reference Reaper #1" java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInterceptorDelegatorBoot
09:17:56,823 ERROR [stderr] (Reference Reaper #1) 	at org.wildfly.common.ref.References$ReaperThread.run(References.java)
09:17:56,823 ERROR [stderr] (Reference Reaper #1) Caused by: java.lang.ClassNotFoundException: com.singularity.ee.agent.appagent.entrypoint.bciengine.FastMethodInterceptorDelegatorBoot from [Module "org.wildfly.common" version 1.6.0.Final from local module loader @7a30d1e6 (finder: local module finder @5891e32e (roots: /opt/jboss/modules,/opt/jboss/modules/system/layers/base))]
09:17:56,824 ERROR [stderr] (Reference Reaper #1) 	at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:200)
09:17:56,824 ERROR [stderr] (Reference Reaper #1) 	at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:410)
09:17:56,824 ERROR [stderr] (Reference Reaper #1) 	at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
09:17:56,825 ERROR [stderr] (Reference Reaper #1) 	at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116)
09:17:56,825 ERROR [stderr] (Reference Reaper #1) 	... 1 more
09:17:56,826 ERROR [stderr] (Reference Reaper #3) java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInterceptorDelegatorBoot
09:17:56,827 ERROR [stderr] (Reference Reaper #3) 	at org.wildfly.common.ref.References$ReaperThread.run(References.java)
09:18:05,627 INFO  [stdout] (AD Agent init) Started AppDynamics Java Agent Successfully.
09:18:41,038 ERROR [org.xnio.nio] (default I/O-2) XNIO000011: Task org.xnio.nio.WorkerThread$SynchTask@191c0b4b failed with an exception: java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInterceptorDelegatorBoot

[MARTINA_MELIAN1 · Accepted solution]

Hi Akshay.Nimbal,

Thank you for posting to community.

It looks like you're encountering a similar issue ("Exception in thread 'Reference Reaper #2' java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInterceptorDelegatorBoot") that's been discussed in a related community post:

You can check out the troubleshooting steps here:

java.lang.NoClassDefFoundError: com/singularity/ee/agent/appagent/entrypoint/bciengine/FastMethodInt‌

Also, just a heads-up: depending on your framework, there are some startup settings required. For JBoss or Wildfly, you need to ensure that the Java Agent and the log manager packages are included in the server startup routine.This is documented here:
https://docs.appdynamics.com/appd/onprem/24.x/24.9/en/application-monitoring/install-app-server-agen...‌

I hope this reference helps. However, let me know if the issue persists. I’d be happy to assist further.

Martina