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https://issues.apache.org/jira/browse/FLINK-14163?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17011689#comment-17011689
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Chesnay Schepler commented on FLINK-14163:
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Can someone explain to me where exactly a task is being deployed 
(\{{Execution#deploy}}) without the futures for slots/partitions being 
completed? Both {{SchedulingUtils#schedulerEager}} and 
{{Execution#scheduleForExecution}} only call {{deploy}} if the future has 
finished.

I don't understand how there could be a pending partition registration during 
deployment.

 

The only I problem I see is that a partition could leak if one of the 
registration fail, since the combined future will never finish and hence the 
partitions will never reach the book-keeping.

> Execution#producedPartitions is possibly not assigned when used
> ---------------------------------------------------------------
>
>                 Key: FLINK-14163
>                 URL: https://issues.apache.org/jira/browse/FLINK-14163
>             Project: Flink
>          Issue Type: Bug
>          Components: Runtime / Coordination
>    Affects Versions: 1.9.0, 1.10.0
>            Reporter: Zhu Zhu
>            Assignee: Yuan Mei
>            Priority: Major
>             Fix For: 1.10.0
>
>
> Currently {{Execution#producedPartitions}} is assigned after the partitions 
> have completed the registration to shuffle master in 
> {{Execution#registerProducedPartitions(...)}}.
> The partition registration is an async interface 
> ({{ShuffleMaster#registerPartitionWithProducer(...)}}), so 
> {{Execution#producedPartitions}} is possible[1] not set when used. 
> Usages includes:
> 1. deploying this task, so that the task may be deployed without its result 
> partitions assigned, and the job would hang. (DefaultScheduler issue only, 
> since legacy scheduler handled this case)
> 2. generating input descriptors for downstream tasks: 
> 3. retrieve {{ResultPartitionID}} for partition releasing: 
> [1] If a user uses Flink default shuffle master {{NettyShuffleMaster}}, it is 
> not problematic at the moment since it returns a completed future on 
> registration, so that it would be a synchronized process. However, if users 
> implement their own shuffle service in which the 
> {{ShuffleMaster#registerPartitionWithProducer}} returns an pending future, it 
> can be a problem. This is possible since customizable shuffle service is open 
> to users since 1.9 (via config "shuffle-service-factory.class").
> To avoid issues to happen, we may either 
> 1. fix all the usages of {{Execution#producedPartitions}} regarding the async 
> assigning, or 
> 2. change {{ShuffleMaster#registerPartitionWithProducer(...)}} to a sync 
> interface



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