FAQ
[ https://issues.apache.org/jira/browse/HADOOP-4927?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Tsz Wo (Nicholas), SZE updated HADOOP-4927:
-------------------------------------------

Component/s: mapred
Issue Type: Bug (was: New Feature)
I believe some users did mention that the feature of having exactly N output files is useful.
I also believe it is useful in some cases, especially when all output files are empty (ah, you may argue that the entire job is not useful in this case :) ). However, it is costly to maintain empty files in HDFS and I believe it is USELESS in many cases. Could we have an option for not creating them or cleaning them?
Part files on the output filesystem are created irrespective of whether the corresponding task has anything to write there
--------------------------------------------------------------------------------------------------------------------------

Key: HADOOP-4927
URL: https://issues.apache.org/jira/browse/HADOOP-4927
Project: Hadoop Core
Issue Type: Bug
Components: mapred
Reporter: Devaraj Das
Fix For: 0.20.0


When OutputFormat.getRecordWriter is invoked, a part file is created on the output filesystem. But the created RecordWriter is not used until the OutputCollector.collect call is made by the task (user's code). This results in empty part files even if the OutputCollector.collect is never invoked by the corresponding tasks.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Search Discussions

Discussion Posts

Previous

Follow ups

Related Discussions

Discussion Navigation
viewthread | post
posts ‹ prev | 6 of 48 | next ›
Discussion Overview
groupcommon-dev @
categorieshadoop
postedDec 22, '08 at 6:01a
activeFeb 23, '09 at 3:19p
posts48
users1
websitehadoop.apache.org...
irc#hadoop

1 user in discussion

Hudson (JIRA): 48 posts

People

Translate

site design / logo © 2022 Grokbase