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https://issues.apache.org/jira/browse/FLINK-12229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16830880#comment-16830880
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BoWang commented on FLINK-12229:
--------------------------------

Thanks [~till.rohrmann].

The advantage of only looking at the input result partitions is obvious. But I 
am wondering there may be some negative effects. 1) Once any result partition 
finishes the consumer vertex will be scheduled and the reset result partition 
infos would be send to the TM separately. That would be a lot of additional 
network communications for updating partition info if the input partition 
number is huge since looking at the IntermediateDataSet all the partition infos 
are composed in the `TaskDeploymentDescriptor`. 2) There may be resource 
deadlock, e.g., considering a job with map-reduce-join job vertices. Both 
reduce and join job vertices has ANY input constraints so parts of the tasks 
could be scheduled but cannot finishes until all the input result partitions 
are ready. When the free resource of the cluster are not enough, the running 
join vertices are waiting for all the input while part of reduce vertices are 
waiting resource to be schedule.

Making SchedulingIntermediateDataSet as part of 
LazyFromSourcesSchedulingStrategy would work, I will do like this.

 

> Implement Lazy Scheduling Strategy
> ----------------------------------
>
>                 Key: FLINK-12229
>                 URL: https://issues.apache.org/jira/browse/FLINK-12229
>             Project: Flink
>          Issue Type: Sub-task
>          Components: Runtime / Coordination
>            Reporter: Gary Yao
>            Assignee: BoWang
>            Priority: Major
>              Labels: pull-request-available
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> Implement a {{SchedulingStrategy}} that covers the functionality of 
> {{ScheduleMode.LAZY_FROM_SOURCES}}, i.e., vertices are scheduled when all the 
> input data are available.
> Acceptance Criteria:
>  * New strategy is tested in isolation using test implementations (i.e., 
> without having to submit a job)



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