Craig Welch created MAPREDUCE-6251:
--------------------------------------

             Summary: JobClient needs additional retries at a higher level to 
address not-immediately-consistent dfs corner cases
                 Key: MAPREDUCE-6251
                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-6251
             Project: Hadoop Map/Reduce
          Issue Type: Bug
          Components: jobhistoryserver
    Affects Versions: 2.2.0
            Reporter: Craig Welch
            Assignee: Craig Welch


The JobClient is used to get job status information for running and completed 
jobs.  Final state and history for a job is communicated from the application 
master to the job history server via a distributed file system - where the 
history is uploaded by the application master to the dfs and then 
scanned/loaded by the jobhistory server.  While HDFS has strong consistency 
guarantees not all Hadoop DFS's do.  When used in conjunction with a 
distributed file system which does not have this guarantee there will be cases 
where the history server may not see an uploaded file, resulting in the dreaded 
"no such job" and a null value for the RunningJob in the client.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to