[
https://issues.apache.org/jira/browse/FLINK-7844?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16206280#comment-16206280
]
Zhenzhong Xu edited comment on FLINK-7844 at 10/16/17 5:46 PM:
---------------------------------------------------------------
[~till.rohrmann] We have a use case where Task Managers will be migrated in a
rolling fashion (with minimum interval in-between). Would this approach allow
checkpoint to continue as soon as fine grained recovery is performed?
IMHO, I think maybe a more appropriate longer-term fix is allowing checkpoint
to be committed individually for each parallel task in an embarrassingly
parallel DAG, that way we can truly achieve no dependencies between the
parallel tasks. Thoughts?
was (Author: zhenzhongxu):
[~till.rohrmann] We have a use case where Task Managers will be migrated in a
rolling fashion (with minimum interval in-between). Would this approach allow
checkpoint to continue as soon as fine grained recovery is performed?
IMHO, I think the maybe a more appropriate longer-term fix is allowing
checkpoint to be committed individually for each parallel task in an
embarrassingly parallel DAG, that way we can truly achieve no dependencies
between the parallel tasks. Thoughts?
> Fine Grained Recovery triggers checkpoint timeout failure
> ---------------------------------------------------------
>
> Key: FLINK-7844
> URL: https://issues.apache.org/jira/browse/FLINK-7844
> Project: Flink
> Issue Type: Bug
> Components: State Backends, Checkpointing
> Affects Versions: 1.4.0, 1.3.2
> Reporter: Zhenzhong Xu
> Assignee: Zhenzhong Xu
> Attachments: screenshot-1.png
>
>
> Context:
> We are using "individual" failover (fine-grained) recovery strategy for our
> embarrassingly parallel router use case. The topic has over 2000 partitions,
> and parallelism is set to ~180 that dispatched to over 20 task managers with
> around 180 slots.
> Observations:
> We've noticed after one task manager termination, even though the individual
> recovery happens correctly, that the workload was re-dispatched to a new
> available task manager instance. However, the checkpoint would take 10 mins
> to eventually timeout, causing all other task managers not able to commit
> checkpoints. In a worst-case scenario, if job got restarted for other reasons
> (i.e. job manager termination), that would cause more messages to be
> re-processed/duplicates compared to the job without fine-grained recovery
> enabled.
> I am suspecting that uber checkpoint was waiting for a previous checkpoint
> that initiated by the old task manager and thus taking a long time to time
> out.
> Two questions:
> 1. Is there a configuration that controls this checkpoint timeout?
> 2. Is there any reason that when Job Manager realizes that Task Manager is
> gone and workload is redispatched, it still need to wait for the checkpoint
> initiated by the old task manager?
> Checkpoint screenshot in attachments.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
