[
https://issues.apache.org/jira/browse/HADOOP-3211?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Harsh J resolved HADOOP-3211.
-----------------------------
Resolution: Not A Problem
The balancer does this today. The BlockManager and its services do not, however.
> Utility to enforce current replication policy on already exitsting blocks
> -------------------------------------------------------------------------
>
> Key: HADOOP-3211
> URL: https://issues.apache.org/jira/browse/HADOOP-3211
> Project: Hadoop Common
> Issue Type: New Feature
> Reporter: Robert Chansler
>
> If the replica placement policy changes, or if the cluster topology changes,
> existing block replicas will not be deliberately moved to implement the new
> policy or to reflect the new topology. The re-replicator and the re-balancer
> always implement the current policy, but a healthy block may never attract
> the attention of either of those facilities.
> In practice, all replicas of a block have been found within a single rack (as
> allowed by the previous _random rack_ placement policy. The {{fsck}} facility
> reports such examples.
> The re-placer utility could follow the model of the re-balancer. Or even be
> part of the re-balancer.
> An alternative implementation would scan the {{fsck}} report for curious
> blocks, and rename a replica block file on the data node, so as to hide it.
> The re-replicator would be expected to create a new replica properly placed.
> (This is a fix up that any administrator could implement.)
> (1761414)
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
