[
https://issues.apache.org/jira/browse/HDFS-14465?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16866035#comment-16866035
]
Wei-Chiu Chuang commented on HDFS-14465:
----------------------------------------
Patch was pushed to trunk, through to branch-3.0.
But it doesn't apply for branch-2. [~caiyicong] would you like to also
contribute a branch-2 patch as well?
> When the Block expected replications is larger than the number of DataNodes,
> entering maintenance will never exit.
> ------------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-14465
> URL: https://issues.apache.org/jira/browse/HDFS-14465
> Project: Hadoop HDFS
> Issue Type: Bug
> Affects Versions: 2.9.2
> Reporter: Yicong Cai
> Assignee: Yicong Cai
> Priority: Major
> Fix For: 3.0.4, 3.3.0, 3.2.1, 3.1.3
>
> Attachments: HDFS-14465.01.patch, HDFS-14465.02.patch
>
>
> Scenes:
> There is a small HDFS cluster with 5 DataNodes; one of them is maintained,
> added to the maintenance list, and set
> dfs.namenode.maintenance.replication.min to 1.
> When refresh Nodes, the NameNode starts checking whether the blocks on the
> node require a new replication.
> The replications of the MapReduce task job file is 10 by default,
> isNeededReplicationForMaintenance will determine to false, and
> isSufficientlyReplicated will determine to false, so the block of the job
> file needs to increase the replication.
> When adding a replication, since the cluster has only 5 DataNodes, all the
> nodes have the replications of the block, chooseTargetInOrder will throw a
> NotEnoughReplicasException, so that the replication cannot be increase, and
> the Entering Maintenance cannot be ended.
> This issue will cause the independent small cluster to be unable to use the
> maintenance mode.
>
> {panel:title=chooseTarget exception log}
> 2019-05-03 23:42:31,008 [31545331] - WARN
> [ReplicationMonitor:BlockPlacementPolicyDefault@431] - Failed to place enough
> replicas, still in need of 1 to reach 5 (unavailableStorages=[],
> storagePolicy=BlockStoragePolicy\{HOT:7, storageTypes=[DISK],
> creationFallbacks=[], replicationFallbacks=[ARCHIVE]}, newBlock=false) For
> more information, please enable DEBUG log level on
> org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy and
> org.apache.hadoop.net.NetworkTopology
> {panel}
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
