[HDFS-1300] Decommissioning nodes does not increase replication priority

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.20.1, 0.20.2, 0.20.3, 0.20-append, 0.21.0, 0.22.0
• Assignee: Dmytro Molkov
• Reporter: Dmytro Molkov
• Created: 14/Jul/10 18:32
• Updated: 06/Feb/15 23:12

Description

Currently when you decommission a node each block is only inserted into neededReplications if it is not there yet. This causes a problem of a block sitting in a low priority queue when all replicas sit on the nodes being decommissioned.
The common usecase for decommissioning nodes for us is proactively exclude them before they went bad, so it would be great to get the blocks at risk onto the live datanodes as quickly as possible.