You are viewing a plain text version of this content. The canonical link for it is here.
Posted to mapreduce-dev@hadoop.apache.org by "Yongjun Zhang (JIRA)" <ji...@apache.org> on 2015/12/14 20:42:46 UTC
[jira] [Created] (MAPREDUCE-6572) Improved incremental data copy of
distcp for truncated file
Yongjun Zhang created MAPREDUCE-6572:
----------------------------------------
Summary: Improved incremental data copy of distcp for truncated file
Key: MAPREDUCE-6572
URL: https://issues.apache.org/jira/browse/MAPREDUCE-6572
Project: Hadoop Map/Reduce
Issue Type: Bug
Reporter: Yongjun Zhang
Assignee: John Zhuge
MAPREDUCE-5899 improves distcp by supporting incremental data copy. That is, if a file is only appended since it was copied last time, only new data need to be copied.
This improvement was done before HDFS truncate feature (HDFS-3107) was implemented. Since we support truncate, if a large file is truncated a little bit, the whole file will still need to be copied, even with the solution of MAPREDUCE-5899.
Creating this jira to improve the situation, by possibly remembering the smallest truncated size, so there is chance to only append from that size on.
Thanks.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)