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Doug Cutting commented on HADOOP-492: ------------------------------------- > I normally am interested only in the final accumulated values of my counters Yes, but others may be interested in counting, e.g., network errors, to judge the health of long-running jobs. Still, I don't think we need to provide updates but every minute or so, which, for many tasks, means only the final values will be transmitted. > Global counters > --------------- > > Key: HADOOP-492 > URL: https://issues.apache.org/jira/browse/HADOOP-492 > Project: Hadoop > Issue Type: New Feature > Components: mapred > Reporter: arkady borkovsky > Assigned To: David Bowen > > It would be nice to have map / reduce job keep aggregated counts for > arbitrary events occuring in its tasks -- the numer of records processed, the > numer of exceptions of a specific type, the number of sentences in passive > voice, whatever the jobs finds useful. > This can be implemented by tasks periodically sending <name, value> pairs to > the jobtracker (in some implementations such messages are piggy-backed on the > heartbeats), so that the job tracker stores all the latests values from each > task and aggregates them on a request. It should also make the aggregated > values available at the job end. The value for a task would be flushed when > the task fails. > #491 and #490 may be related to this one. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.