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https://issues.apache.org/jira/browse/HDFS-1172?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14738214#comment-14738214
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Masatake Iwasaki commented on HDFS-1172:
----------------------------------------
Thanks for the update [~azuryy], but the patch can not be applied to current
trunk.
I applied a part of the patch relating to
{{TestReplication#testNoExtraReplicationWhenBlockReceivedIsLate}} and ran the
TestReplication but the assertion below passed without fix of BlockManager. The
test seems not to be able to reproduce the issue.
{code}
// Check that none of the datanodes have serviced a replication request.
// i.e. that the NameNode didn't schedule any spurious replication.
assertNoReplicationWasPerformed(cluster);
{code}
> Blocks in newly completed files are considered under-replicated too quickly
> ---------------------------------------------------------------------------
>
> Key: HDFS-1172
> URL: https://issues.apache.org/jira/browse/HDFS-1172
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 0.21.0
> Reporter: Todd Lipcon
> Attachments: HDFS-1172-150907.patch, HDFS-1172.patch, hdfs-1172.txt,
> hdfs-1172.txt, replicateBlocksFUC.patch, replicateBlocksFUC1.patch,
> replicateBlocksFUC1.patch
>
>
> I've seen this for a long time, and imagine it's a known issue, but couldn't
> find an existing JIRA. It often happens that we see the NN schedule
> replication on the last block of files very quickly after they're completed,
> before the other DNs in the pipeline have a chance to report the new block.
> This results in a lot of extra replication work on the cluster, as we
> replicate the block and then end up with multiple excess replicas which are
> very quickly deleted.
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