[HDFS-7374] Allow decommissioning of dead DataNodes

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.7.0
• Assignee: Zhe Zhang
• Reporter: Zhe Zhang
• Created: 06/Nov/14 18:32
• Updated: 05/Jan/21 17:39
• Resolved: 19/Nov/14 06:20

Description

We have seen the use case of decommissioning DataNodes that are already dead or unresponsive, and not expected to rejoin the cluster.

The logic introduced by HDFS-6791 will mark those nodes as DECOMMISSION_INPROGRESS, with a hope that they can come back and finish the decommission work. If an upper layer application is monitoring the decommissioning progress, it will hang forever.

Issue Links

• causes: HDFS-15761 Dead NORMAL DN shouldn't transit to DECOMMISSIONED immediately
• is related to: HDFS-11609 Some blocks can be permanently lost if nodes are decommissioned while dead
• is related to: HDFS-6791 A block could remain under replicated if all of its replicas are on decommissioned nodes