[
https://issues.apache.org/jira/browse/HADOOP-1915?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Owen O'Malley updated HADOOP-1915:
----------------------------------
Assignee: Tom White (was: Christopher Zimmerman)
Tom,
Your patch is a lot more expensive in terms of cpu time, especially in the
merge of counters between tasks that is done in the Job Tracker. The ids for
each counter were used to speed up access within each group. It probably makes
sense to use a tree map instead of a hash map, so that merges between sets of
counters can use the sorted nature of tree maps...
Of course, just adding the string-based method in the reporter with the ids
would have been even easier. *smile*
> adding counters methods using String (as opposed to Enum)
> ---------------------------------------------------------
>
> Key: HADOOP-1915
> URL: https://issues.apache.org/jira/browse/HADOOP-1915
> Project: Hadoop Core
> Issue Type: New Feature
> Environment: all
> Reporter: Alejandro Abdelnur
> Assignee: Tom White
> Priority: Minor
> Fix For: 0.17.0
>
> Attachments: hadoop-1915.patch
>
>
> Currently to use the counters from within Map/Reduce code Enums have to be
> used, the Enum class defines the group and the Enum itself the counter.
> Internally they are converted to Strings (the class name and the enum
> toString) and you can retrieve them as strings from the client API.
> Using dynamic counters (driven by configuration of the map/reduce) is not
> easy with the counters Enum based API. For example, currently I have an Enum
> class with 50 enums and we have to map the cardinality to the counter name on
> the client. This is cumbersome.
> This could be easily improve by adding a String based counter method
> increment(String group, String counter, long count) to allow use of the
> counters without Enums.
> Internally this method already exists, so the changes are minimal.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
