[
https://issues.apache.org/jira/browse/TEZ-2103?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14366481#comment-14366481
]
Alok Asok commented on TEZ-2103:
--------------------------------
Hi,
I am a very keen to understand and work on Tez. I have gone through few
technical papers and tez documentation in this regard. It would be very helpful
to clearly understand the use-case of the task if somebody can give me a
clearer understanding of the vertex manager plugin.
Thanks
> Implement a Partial completion VertexManagerPlugin
> --------------------------------------------------
>
> Key: TEZ-2103
> URL: https://issues.apache.org/jira/browse/TEZ-2103
> Project: Apache Tez
> Issue Type: New Feature
> Reporter: Gopal V
> Labels: gsoc, gsoc2015, hadoop, java, tez
>
> Currently, there is no sibling communication between tasks - this implies
> that a task can be completed by the first vertex in a wave of tasks, but the
> entire wave of tasks has to complete before success can be reported.
> This occurs in limit + filter query patterns common between the data access
> engines.
> {code}
> select * from data where x > 1 limit 10;
> {code}
> will run through a full-table scan worth of tasks to generate 10 rows per
> task, to aggregate it to produce the final 10 row result.
> The VertexManager receives counters/events early enough to short-circuit the
> rest of the vertex tasks, to prevent the remainder of tasks from getting
> scheduled when the limit condition has been satisfied by an initial sub-set
> of the tasks.
> This is a specialization of the VertexManagerPlugin for this common case
> scheduling pattern.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
