[HDFS-8127] NameNode Failover during HA upgrade can cause DataNode to finalize upgrade

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 2.6.1, 2.8.0, 2.7.1, 3.0.0-alpha1
• Component/s: ha
• Labels: 2.6.1-candidate
• Target Version/s: 2.7.1
• Hadoop Flags: Reviewed
• Assignee: Jing Zhao
• Reporter: Jing Zhao
• Created: 10/Apr/15 17:27
• Updated: 05/Jan/17 22:42
• Resolved: 14/Apr/15 22:17

Description

Currently for HA upgrade (enabled by HDFS-5138), we use -bootstrapStandby to initialize the standby NameNode. The standby NameNode does not have the previous directory thus it does not know that the cluster is in the upgrade state. If NN failover happens, as response of block reports, the new ANN will tell DNs to finalize the upgrade thus make it impossible to rollback again.

Issue Links

• is broken by: HDFS-5138 Support HDFS upgrade in HA
• requires: HDFS-3443 Fix NPE when namenode transition to active during startup by adding checkNNStartup() in NameNodeRpcServer