Hey Dlmuthu, Not an expert in Helix, but from exceptions it seems, system is entering in a state not expected by reflection. I feel https://github.com/apache/helix/blob/master/helix-core/src/main/java/org/apache/helix/messaging/handling/HelixStateTransitionHandler.java#L295 is triggering this exception. As mentioned in the later part of the stack trace and from Helix Apache Docs <http://helix.apache.org/0.7.1-docs/tutorial_agent.html> *("Helix is built on the following assumption: if your distributed resource is modeled by a finite state machine, then Helix can tell participants when they should transition between states. In the Java API, this means implementing transition callbacks. In the Helix agent API, this means providing commands than can run for each transition"),* did you implement *transition callback* for these tasks?
On Thu, Nov 16, 2017 at 10:01 AM, DImuthu Upeksha < [email protected]> wrote: > Hi Devs, > > I'm working on the technology evaluation to re architecture Apache > Airavata task execution framework and Helix seems like a good candidate for > that as it has an in built distributed generic workflow execution > capability. After going through several tutorials, I tried to implement a > simple workflow on Helix to demonstrate following transition > > Data Collecting Job -> Command Executing Job -> Data Uploading Job > > I managed to implement this using a Participant node that includes all the > tasks required for above workflow. However my goal is to implement > specialized Participants for each Job type. For example, Participant 1 > knows only about the tasks to perform Data Collecting Job and Participant > knows only about the task to perform Command Executing Job. When I tried to > implement such Participants, I got following error from Participant 1. I > can share the code samples that I have tried but before that I need to know > whether my approach is compatible with Helix's design? Does Helix require > all the Participants to be homogeneous? > > Executing data collecting > 675892 [pool-2-thread-8] ERROR > org.apache.helix.messaging.handling.HelixStateTransitionHandler > - Exception while executing a state transition task Airavata_Workflow_ > commandExecuteJob_0 > java.lang.reflect.InvocationTargetException > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at sun.reflect.NativeMethodAccessorImpl.invoke( > NativeMethodAccessorImpl.java:62) > at sun.reflect.DelegatingMethodAccessorImpl.invoke( > DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:498) > at org.apache.helix.messaging.handling.HelixStateTransitionHandler.invoke( > HelixStateTransitionHandler.java:344) > at org.apache.helix.messaging.handling.HelixStateTransitionHandler. > handleMessage(HelixStateTransitionHandler.java:290) > at org.apache.helix.messaging.handling.HelixTask.call(HelixTask.java:84) > at org.apache.helix.messaging.handling.HelixTask.call(HelixTask.java:41) > at java.util.concurrent.FutureTask.run(FutureTask.java:266) > at java.util.concurrent.ThreadPoolExecutor.runWorker( > ThreadPoolExecutor.java:1149) > at java.util.concurrent.ThreadPoolExecutor$Worker.run( > ThreadPoolExecutor.java:624) > at java.lang.Thread.run(Thread.java:748) > Caused by: java.lang.IllegalStateException: No callback implemented for > task COMMAND > at org.apache.helix.task.TaskStateModel.startTask(TaskStateModel.java:302) > at org.apache.helix.task.TaskStateModel.onBecomeRunningFromInit( > TaskStateModel.java:69) > ... 12 more > 675900 [pool-2-thread-8] ERROR > org.apache.helix.participant.statemachine.StateModel > - Default rollback method invoked on error. Error Code: ERROR > 675908 [pool-2-thread-8] ERROR org.apache.helix.messaging.handling.HelixTask > - Message execution failed. msgId: 8d9a08c9-0ae7-419a-8940-6b8e6e7c1ecb, > errorMsg: java.lang.reflect.InvocationTargetException > 675922 [pool-2-thread-8] ERROR > org.apache.helix.messaging.handling.HelixStateTransitionHandler > - Skip internal error. errCode: ERROR, errMsg: null > > Thanks > Dimuthu > -- Thanks and regards, Ajinkya Dhamnaskar Student ID : 0003469679 Masters (CS) +1 (812) 369- 5416
