[
https://issues.apache.org/jira/browse/HADOOP-2175?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12576208#action_12576208
]
Runping Qi commented on HADOOP-2175:
------------------------------------
Re-executing the mappers will likely be the correct action in most cases.
Even for some cases where this is not optimal, its cost will not be that
expensive.
Thus, I think that is the right behavior, before comebody comes up with a
simple and effective alternative
> Blacklisted hosts may not be able to serve map outputs
> ------------------------------------------------------
>
> Key: HADOOP-2175
> URL: https://issues.apache.org/jira/browse/HADOOP-2175
> Project: Hadoop Core
> Issue Type: Bug
> Components: mapred
> Reporter: Runping Qi
> Assignee: Arun C Murthy
>
> After a node fails 4 mappers (tasks), it is added to blacklist thus it will
> no longer accept tasks.
> But, it will continue serve the map outputs of any mappers that ran
> successfully there.
> However, the node may not be able serve the map outputs either.
> This will cause the reducers to mark the corresponding map outputs as from
> slow hosts,
> but continue to try to get the map outputs from that node.
> This may lead to waiting forever.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
