[HDFS-7082] When replication factor equals number of data nodes, corrupt replica will never get substituted with good replica

• Type: Bug
• Status: In Progress
• Priority: Minor
• Resolution: Unresolved
• Component/s: namenode
• Assignee: Srikanth Upputuri
• Reporter: Srikanth Upputuri
• Created: 17/Sep/14 10:34
• Updated: 18/Sep/14 10:13

Description

BlockManager will not invalidate a corrupt replica if this brings down the total number of replicas below replication factor (except if the corrupt replica has a wrong genstamp). On clusters where the replication factor = total data nodes, a new replica can not be created from a live replica as all the available datanodes already have a replica each. Because of this, the corrupt replicas will never be substituted with good replicas, so will never get deleted. Sooner or later all replicas may get corrupt and there will be no live replicas in the cluster for this block.