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Yongjun Zhang commented on HADOOP-11794: ---------------------------------------- Had a discussion with [~atm] (thanks ATM), we now agreed on an approach that - relax the file system checking, - adding the doc as [~steve_l] commented, stating concat need to be supported when the feature is turned on - creating follow-up jiras to add unit tests and validation for ADLS and other file systems - for file systems that don't support getBlockLocations or concat, create jiras to let them fail the run sooner. Please be aware of the situation I pointed out in my last comment, that if user enabled this feature for file systems that don't support concat, distcp may fail in the middle of a run and make the file system into an inconsistent state. Does that sound good to all? Thanks. > distcp can copy blocks in parallel > ---------------------------------- > > Key: HADOOP-11794 > URL: https://issues.apache.org/jira/browse/HADOOP-11794 > Project: Hadoop Common > Issue Type: Improvement > Components: tools/distcp > Affects Versions: 0.21.0 > Reporter: dhruba borthakur > Assignee: Yongjun Zhang > Attachments: HADOOP-11794.001.patch, HADOOP-11794.002.patch, > HADOOP-11794.003.patch, HADOOP-11794.004.patch, HADOOP-11794.005.patch, > HADOOP-11794.006.patch, HADOOP-11794.007.patch, HADOOP-11794.008.patch, > MAPREDUCE-2257.patch > > > The minimum unit of work for a distcp task is a file. We have files that are > greater than 1 TB with a block size of 1 GB. If we use distcp to copy these > files, the tasks either take a long long long time or finally fails. A better > way for distcp would be to copy all the source blocks in parallel, and then > stich the blocks back to files at the destination via the HDFS Concat API > (HDFS-222) -- This message was sent by Atlassian JIRA (v6.3.15#6346) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org