[HDFS-12049] Recommissioning live nodes stalls the NN

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Duplicate
• Affects Version/s: 2.6.0
• Target Version/s: 3.3.0
• Assignee: Unassigned
• Reporter: Daryn Sharp
• Created: 27/Jun/17 15:48
• Updated: 21/Oct/19 23:23
• Resolved: 21/Oct/19 23:23

Description

A node refresh will recommission included nodes that are alive and in decommissioning or decommissioned state. The recommission will scan all blocks on the node, find over replicated blocks, chose an excess, queue an invalidate.

The process is expensive and worsened by overhead of storage types (even when not in use). It can be especially devastating because the write lock is held for the entire node refresh. Recommissioning 67 nodes with ~500k blocks/node stalled rpc services for over 4 mins.

Issue Links

• duplicates: HDFS-10477 Stop decommission a rack of DataNodes caused NameNode fail over to standby