[ http://issues.apache.org/jira/browse/HADOOP-403?page=comments#action_12427732 ] Runping Qi commented on HADOOP-403: -----------------------------------
In my app, I added an OutputCollector variable (and a Reporter variable if necessary) in my Map/Reduce classes so that the close method can access them. Those variables are assigned only once my the first call to Map/Reduce method. If the framework should offer help here, we can introduce to Closable a method setCollector(OutputCollector) and setReporter(Reporter). When the framework creates a Mapper/Reducer object, it calls these methods. > close method in a Mapper should be provided with OutputCollector and a > Reporter > ------------------------------------------------------------------------------- > > Key: HADOOP-403 > URL: http://issues.apache.org/jira/browse/HADOOP-403 > Project: Hadoop > Issue Type: Improvement > Components: mapred > Affects Versions: 0.5.0 > Environment: all > Reporter: Milind Bhandarkar > Assigned To: Milind Bhandarkar > Fix For: 0.6.0 > > > For mappers with side-effects, or mappers that work as aggregators (i.e. no > output on individual key-value pairs, but an aggregate output at the end of > all key-value pairs), output should be performed in the close method. For > this purpose, we need to supply output collector and reporter to the close > method of Mapper. This involves interface change, though. Thoughts ? -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
