[
https://issues.apache.org/jira/browse/HDFS-7442?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Ming Ma resolved HDFS-7442.
---------------------------
Resolution: Duplicate
HDFS-7411 has addressed this issue.
> Optimization for decommission-in-progress check
> -----------------------------------------------
>
> Key: HDFS-7442
> URL: https://issues.apache.org/jira/browse/HDFS-7442
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: namenode
> Affects Versions: 2.6.0
> Reporter: Ming Ma
>
> 1. {{isReplicationInProgress }} currently rescan all blocks of a given node
> each time the method is called; it becomes less efficient as more of its
> blocks become fully replicated. Each scan takes FS lock.
> 2. As discussed in HDFS-7374, if the node becomes dead during decommission,
> it is useful if the dead node can be marked as decommissioned after all its
> blocks are fully replicated. Currently there is no way to check the blocks of
> dead decomm-in-progress nodes, given the dead node is removed from blockmap.
> There are mitigations for these limitations. Set
> dfs.namenode.decommission.nodes.per.interval to small value for reduce the
> duration of lock. HDFS-7409 uses global FS state to tell if a dead node's
> blocks are fully replicated.
> To address these scenarios, it will be useful to track the
> decommon-in-progress blocks separately.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
