You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@samza.apache.org by "Shanthoosh Venkataraman (JIRA)" <ji...@apache.org> on 2018/04/16 23:26:00 UTC
[jira] [Created] (SAMZA-1663) StreamProcessor fails after
reestablishing zookeeper session.
Shanthoosh Venkataraman created SAMZA-1663:
----------------------------------------------
Summary: StreamProcessor fails after reestablishing zookeeper session.
Key: SAMZA-1663
URL: https://issues.apache.org/jira/browse/SAMZA-1663
Project: Samza
Issue Type: Bug
Reporter: Shanthoosh Venkataraman
Assignee: Shanthoosh Venkataraman
*Problem:*
StreamProcessor fails sporadically after reestablishing the zookeeper session.
*Analysis:*
Currently in ZkJobCoordinator, buffered stale events in the leader stream processor before a zookeeper session disconnect causes the StreamProcessor to fail after session reconnect. Consider the following scenario:
A. Leader receives processor change notification from zookeeper.
B. Before it acts on the notification, zookeeper session expiration occurs.
C. Leader stream processor disconnects from the group and joins the group as a follower.
D. It acts upon the stale events (generated for some non-existent processors), which ends up killing it.
*Relevant stacktrace:*
As we can see in this case, before the session expiration there are two processorIds viz [000000001, 000000002]. After the session expiration, alive processorIds were [000000003, 000000004]. StreamProcessor failed since the leader tries to generate JobModel based upon stale processorIds [000000001, 000000002] after zookeeper session reconnect.
{code:java}
```
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkJobCoordinator - Got new session created event for processor=0000000001
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkJobCoordinator - register zk controller for the new session
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils - Created ephemeral path: /app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193/test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-coordinationData/processors/0000000004 for processor: svenkata-mn1.linkedin.biz 0000000001 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils - Found these children - [0000000003, 0000000004]
[ZkClient-EventThread-329-127.0.0.1:53447] WARN org.apache.samza.zk.ZkUtils - ALLOWING handleDataChanged for ProcessorChangeHandler from wrong generation. current generation=1; callback generation= 1
[ZkClient-EventThread-329-127.0.0.1:53447] INFO org.apache.samza.zk.ZkControllerImpl - ZkControllerImpl::ProcessorChangeHandler::handleChildChange - Path: /app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f819 3/test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-coordinationData/processors Current Children: [0000000003, 0000000004]
[ZkClient-EventThread-329-127.0.0.1:53447] INFO org.apache.samza.zk.ZkJobCoordinator - ZkJobCoordinator::onProcessorChange - list of processors changed! List size=2
[ZkClient-EventThread-329-127.0.0.1:53447] INFO org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future of action: OnProcessorChange
[ZkClient-EventThread-329-127.0.0.1:53447] INFO org.apache.samza.zk.ScheduleAfterDebounceTime - Scheduled action: OnProcessorChange to run after: 30000 milliseconds.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils - Found these children - [0000000003, 0000000004]
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkLeaderElector - tryBecomeLeader: index = 1 for path=/app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193/test-app-name-e4bb9daa-d00d-452 c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-coordinationData/processors/0000000004 out of [0000000003, 0000000004]
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkLeaderElector - Index = 1 Not eligible to be a leader yet!
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkLeaderElector - [Processor-0000000001] Subscribing data change for 0000000003
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkLeaderElector - [Processor-0000000001] Predecessor still exists. Current subscription is valid. Continuing as non-leader.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils - Current version for zk root node: /app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193/test-app-name-e4bb9daa-d00d-452c-bf7d-e96 25c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-coordinationData is 1.0, expected version is 1.0
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils - subscribing for jm version change at:/app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193/test-app-name-e4bb9daa-d00d-452c-bf7d -e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-coordinationData/JobModelGeneration/jobModelVersion
[ZkClient-EventThread-291-127.0.0.1:53447] WARN org.apache.samza.zk.ZkUtils - SKIPPING handleDataChanged for ProcessorChangeHandler from wrong generation. current generation=1; callback generation= 0
[ZkClient-EventThread-291-127.0.0.1:53447] WARN org.apache.samza.zk.ZkUtils - SKIPPING handleDataChanged for ZkBarrierChangeHandler from wrong generation. current generation=1; callback generation= 0
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkLeaderElector - [Processor-0000000001] Data deleted on path /app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193/test-app-name-e4bb9daa- d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-coordinationData/processors/0000000000. Predecessor went away. So, trying to become leader again...
[ZkClient-EventThread-291-127.0.0.1:53447] WARN org.apache.samza.zk.ZkUtils - SKIPPING handleDataChanged for PreviousProcessorChangeListener from wrong generation. curGen=1; cb gen= 0
[ZkClient-EventThread-291-127.0.0.1:53447] WARN org.apache.samza.zk.ZkUtils - SKIPPING handleDataChanged for ZkJobModelVersionChangeHandler from wrong generation. curGen=1; cb gen= 0
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkJobCoordinator - Got syncconnected event for processor=0000000001.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future of action: ZK_SESSION_ERROR
[debounce-thread-0] INFO org.apache.samza.zk.ZkUtils - Found these children - [0000000001, 0000000002]
[debounce-thread-0] INFO org.apache.samza.zk.ZkUtils - Found these processorIds - []
[debounce-thread-0] INFO org.apache.samza.zk.ZkJobCoordinator - Generating new JobModel with processors: [].
[debounce-thread-0] INFO org.apache.samza.zk.ZkUtils - read the model ver=2 from /app-test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa-d00d-452c-bf7d-e9625c8f8193/test-app-name-e4bb9daa-d00d-452c-bf7d-e9625c8f8193-test-app-id-e4bb9daa- d00d-452c-bf7d-e9625c8f8193-coordinationData/JobModelGeneration/jobModels/2
[debounce-thread-0] INFO org.apache.samza.coordinator.JobModelManager$ - SystemStreamPartitionGrouper org.apache.samza.container.grouper.stream.GroupByPartition@33169a55 has grouped the SystemStreamPartitions into 5 tasks with the following taskNames: [Partition 1, Partition 0, Partition 3, Partition 2, Partition 4]
[debounce-thread-0] ERROR org.apache.samza.zk.ScheduleAfterDebounceTime - Execution of action: OnProcessorChange failed.
java.lang.IllegalArgumentException: Must have at least one container
at org.apache.samza.container.grouper.task.GroupByContainerIds.group(GroupByContainerIds.java:66)
at org.apache.samza.coordinator.JobModelManager$.readJobModel(JobModelManager.scala:208)
at org.apache.samza.coordinator.JobModelManager.readJobModel(JobModelManager.scala)
at org.apache.samza.zk.ZkJobCoordinator.generateNewJobModel(ZkJobCoordinator.java:354)
at org.apache.samza.zk.ZkJobCoordinator.doOnProcessorChange(ZkJobCoordinator.java:241)
at org.apache.samza.zk.ZkJobCoordinator.lambda$onProcessorChange$1(ZkJobCoordinator.java:225)
at org.apache.samza.zk.ScheduleAfterDebounceTime.lambda$getScheduleableAction$0(ScheduleAfterDebounceTime.java:153)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
```{code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)