[
https://issues.apache.org/jira/browse/TEZ-3984?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16594304#comment-16594304
]
Gopal V commented on TEZ-3984:
------------------------------
Specific sequence of events is - input throws exception.
{code}
2018-08-27T17:25:15,579 WARN [TezTR-437616_7273_9_0_0_0
(1520459437616_7273_9_00_000000_0)] runtime.LogicalIOProcessorRuntimeTask:
Ignoring exception when closing input calls(cleanup). Exception
class=java.io.IOException, message ...
{code}
Output gets closed for memory recovery
{code}
2018-08-27T17:25:15,579 INFO [TezTR-437616_7273_9_0_0_0
(1520459437616_7273_9_00_000000_0)] impl.PipelinedSorter: Reducer 2: Starting
flush of map output
{code}
Sorter pushes event to the output context directly
{code}
2018-08-27T17:25:15,990 INFO [TezTR-437616_7273_9_0_0_0
(1520459437616_7273_9_00_000000_0)] impl.PipelinedSorter: Reducer 2: Adding
spill event for spill (final update=true), spillId=0
{code}
And the Reducer 2 gets the event routed to it.
> Shuffle: Out of Band DME event sending causes errors
> ----------------------------------------------------
>
> Key: TEZ-3984
> URL: https://issues.apache.org/jira/browse/TEZ-3984
> Project: Apache Tez
> Issue Type: Bug
> Affects Versions: 0.8.4, 0.9.1, 0.10.0
> Reporter: Gopal V
> Priority: Critical
> Labels: correctness
>
> In case of a task Input throwing an exception, the outputs are also closed in
> the LogicalIOProcessorRuntimeTask.cleanup().
> Cleanup ignore all the events returned by output close, however if any output
> tries to send an event out of band by directly calling
> outputContext.sendEvents(events), then those events can reach the AM before
> the task failure is reported.
> This can cause correctness issues with shuffle since zero sized events can be
> sent out due to an input failure and downstream tasks may never reattempt a
> fetch from the valid attempt.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
