[HDFS-13295] Namenode doesn't leave safemode if dfs.namenode.safemode.replication.min set < dfs.namenode.replication.min

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Component/s: namenode

Environment

CDH 5.11 with HDFS-8716 backported.

dfs.namenode.replication.min=2
dfs.namenode.safemode.replication.min=1

 

• Assignee: Nicolas Fraison
• Reporter: Nicolas Fraison
• Created: 15/Mar/18 16:20
• Updated: 23/Jun/21 14:47

Description

When we set dfs.namenode.safemode.replication.min < dfs.namenode.replication.min from HDFS-8716 patch the number of replica for which it will increase the safe block count
must be equal to dfs.namenode.safemode.replication.min in `FSNamesystem.incrementSafeBlockCount`

When reading modification from edits, the replica number for new blocks is set at min(numNodes,
dfs.namenode.replication.min) in BlockManager.completeBlock which is greater than dfs.namenode.safemode.replication.min.
Due to that safe block count never reach number of available blocks and namenode doesn't leave automatically the safemode