[HADOOP-9608] ZKFC should abort if it sees an unrecognized NN become active

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.0-alpha1
• Component/s: ha
• Assignee: Unassigned
• Reporter: Todd Lipcon
• Created: 30/May/13 18:05
• Updated: 12/May/16 18:26

Description

We recently had an issue where one NameNode and ZKFC was updated to a new configuration/IP address but the ZKFC on the other node was not rebooted. Then, next time a failover occurred, the second ZKFC was not able to become active because the data in the ActiveBreadCrumb didn't match the data in its own configuration:

org.apache.hadoop.ha.ActiveStandbyElector: Exception handling the winning of election
java.lang.IllegalArgumentException: Unable to determine service address for namenode 'XXXX'

To prevent this from happening, whenever the ZKFC sees a new NN become active, it should check that it's properly able to instantiate a ServiceTarget for it, and if not, abort (since this ZKFC wouldn't be able to handle a failover successfully)