[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed after
zookeeper session reconnect since it tried to generate JobModel for
non-existent processors([1, 2]).
{code:java}
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkJobCoordinator - Got new session created event for
processor=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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/04
out of [03, 04]
[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-01] Subscribing data
change for 03
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] 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.ZkJobCoordinator - Got syncconnected event for
processor=01. [ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future
of action: ZK_SESSION_ERROR
15:16:50.417 [DEBUG] [TestEventLogger] 540098 [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
15:16:50.415 [DEBUG] [TestEventLogger] 540096 [debounce-thread-0] INFO
org.apache.samza.zk.ZkUtils - Found these children - [01, 02]
15:16:50.416 [DEBUG] [TestEventLogger] 540096 [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
[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed after
zookeeper session reconnect since it tried to generate JobModel for
non-existent processors([1, 2]).
{code:java}
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkJobCoordinator - Got new session created event for
processor=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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/04
out of [03, 04]
[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-01] Subscribing data
change for 03
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] 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.ZkJobCoordinator - Got syncconnected event for
processor=01. [ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future
of action: ZK_SESSION_ERROR
15:16:50.417 [DEBUG] [TestEventLogger] 540098 [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
15:16:50.415 [DEBUG] [TestEventLogger] 540096 [debounce-thread-0] INFO
org.apache.samza.zk.ZkUtils - Found these children - [01, 02]
15:16:50.416 [DEBUG] [TestEventLogger] 540096 [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
[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed after
zookeeper session reconnect since it tried to generate JobModel for
non-existent processors([1, 2]).
{code:java}
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkJobCoordinator - Got new session created event for
processor=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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/04
out of [03, 04]
[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-01] Subscribing data
change for 03
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] 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
15:16:50.417 [DEBUG] [TestEventLogger] 540098 [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```[ZkClient-EventThread-291-127.0.0.1:53447]
INFO org.apache.samza.zk.ZkJobCoordinator - Got syncconnected event for
processor=01.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future
of action: ZK_SESSION_ERROR
15:16:50.415 [DEBUG] [TestEventLogger] 540096 [debounce-thread-0] INFO
org.apache.samza.zk.ZkUtils - Found these children - [01, 02]
15:16:50.416 [DEBUG] [TestEventLogger] 540096 [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
[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed after
zookeeper session reconnect since it tried to generate JobModel for
non-existent processors([1, 2]).
{code:java}
```
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkJobCoordinator - Got new session created event for
processor=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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/04
out of [03, 04]
[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-01] Subscribing data
change for 03
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] 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
15:16:50.417 [DEBUG] [TestEventLogger] 540098 [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```[ZkClient-EventThread-291-127.0.0.1:53447]
INFO org.apache.samza.zk.ZkJobCoordinator - Got syncconnected event for
processor=01.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future
of action: ZK_SESSION_ERROR
15:16:50.415 [DEBUG] [TestEventLogger] 540096 [debounce-thread-0] INFO
org.apache.samza.zk.ZkUtils - Found these children - [01, 02]
15:16:50.416 [DEBUG] [TestEventLogger] 540096 [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
[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed after
zookeeper session reconnect since it tried to generate JobModel for
non-existent processors([1, 2]).
{code:java}
```
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkJobCoordinator - Got new session created event for
processor=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
```651519 15:16:29.792 [DEBUG] [TestEventLogger] 519474
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
651520 15:16:29.792 [DEBUG] [TestEventLogger] 519474
[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/04
out of [03, 04]
651521 15:16:29.792 [DEBUG] [TestEventLogger] 519474
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - Index = 1 Not eligible to be a leader yet!
651522 15:16:29.792 [DEBUG] [TestEventLogger] 519474
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] Subscribing data
change for 03
651523 15:16:29.793 [DEBUG] [TestEventLogger] 519475
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] Predecessor still
exists. Current subscription is valid. Continuing as non-leader.
651524 15:16:29.794 [DEBUG] [TestEventLogger] 519476
[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
15:16:50.417 [DEBUG] [TestEventLogger] 540098 [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```[ZkClient-EventThread-291-127.0.0.1:53447]
INFO org.apache.samza.zk.ZkJobCoordinator - Got syncconnected event for
processor=01.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ScheduleAfterDebounceTime - Attempting to cancel the future
of action: ZK_SESSION_ERROR
15:16:50.415 [DEBUG] [TestEventLogger] 540096 [debounce-thread-0] INFO
org.apache.samza.zk.ZkUtils - Found these children - [01, 02]
15:16:50.416 [DEBUG] [TestEventLogger] 540096 [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
[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed after
zookeeper session reconnect since it tried to generate JobModel for
non-existent processors([1, 2]).
{code:java}
```
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkJobCoordinator - Got new session created event for
processor=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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: [03, 04]
[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: 3 milliseconds.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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/04
out of [03, 04]
[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-01] Subscribing data
change for 03
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] 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
[jira] [Updated] (SAMZA-1663) StreamProcessor fails after reestablishing zookeeper session.
[
https://issues.apache.org/jira/browse/SAMZA-1663?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shanthoosh Venkataraman updated SAMZA-1663:
---
Description:
*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 which were buffered in its worker
queue((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 [1, 2]. After the session expiration, alive
processorIds were [3, 4]. StreamProcessor failed since the
leader tries to generate JobModel based upon stale processorIds [1,
2] 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=01
[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/04
for processor: svenkata-mn1.linkedin.biz 01 in zookeeper.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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: [03, 04]
[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: 3 milliseconds.
[ZkClient-EventThread-291-127.0.0.1:53447] INFO org.apache.samza.zk.ZkUtils -
Found these children - [03, 04]
[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/04
out of [03, 04]
[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-01] Subscribing data
change for 03
[ZkClient-EventThread-291-127.0.0.1:53447] INFO
org.apache.samza.zk.ZkLeaderElector - [Processor-01] 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
