[ 
https://issues.apache.org/jira/browse/MAPREDUCE-207?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13997964#comment-13997964
 ] 

Gera Shegalov commented on MAPREDUCE-207:
-----------------------------------------

[[email protected]], thanks for your 
[comment|https://issues.apache.org/jira/browse/MAPREDUCE-5887?focusedCommentId=13997431&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13997431]
  in MAPREDUCE-5887. Moving it to here.

bq. One test to try there is what happens when the blocksize is reported as 
very, very small (you can configure this in swiftfs). in the client this will 
cause the submitting process to OOM and fail. Presumably the same outcome in 
the AM is the simplest to implement -we just need to make sure that YARN 
recognises this as a failure and only tries a couple of times

OOM's as any other AM failure are treated as an Application attempt failure 
({{yarn.resourcemanager.am.max-attempts}}). We've experienced such issues in 
production, and it is actually usually indirectly related to splits, i.e. the 
job state comprising all map and reduce attempts is too big for the default 
MR-AM container size. 

Before doing the work on moving split calculation to MR-AM, I was actually 
thinking about auto-tuning {{yarn.app.mapreduce.am.resource.mb}} and Xmx opts 
in JobSubmitter. However, even if the split calculation happens in AM, we can 
come up with an AM-RM RPC like "start a new attempt with the new settings".

> Computing Input Splits on the MR Cluster
> ----------------------------------------
>
>                 Key: MAPREDUCE-207
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-207
>             Project: Hadoop Map/Reduce
>          Issue Type: New Feature
>          Components: applicationmaster, mrv2
>            Reporter: Philip Zeyliger
>            Assignee: Arun C Murthy
>         Attachments: MAPREDUCE-207.patch, MAPREDUCE-207.v02.patch, 
> MAPREDUCE-207.v03.patch
>
>
> Instead of computing the input splits as part of job submission, Hadoop could 
> have a separate "job task type" that computes the input splits, therefore 
> allowing that computation to happen on the cluster.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Reply via email to