[HDFS-2804] SBN should not mark blocks under-replicated when exiting safemode

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: HA branch (HDFS-1623)
• Fix Version/s: HA branch (HDFS-1623)
• Component/s: ha, namenode
• Target Version/s: HA branch (HDFS-1623)
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 17/Jan/12 19:27
• Updated: 24/Jan/12 12:56
• Resolved: 23/Jan/12 22:23

Description

In testing on a cluster, I restarted with one fewer datanodes than previously. This caused a few thousand blocks to be under-replicated. Similar to HDFS-2795, I saw the under-replicated blocks on the SBN, slowly decreasing as the replication thread ran. This seems to be because we process the replication queue when exiting safemode, even if in standby mode. It also reports many "missing blocks" in the NN UI which are slowly decreasing.