[YARN-3006] Improve the error message when attempting manual failover with auto-failover enabled

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.6.0
• Fix Version/s: 2.8.0, 2.7.1, 3.0.0-alpha1
• Target Version/s: 2.8.0, 2.7.1
• Assignee: Akira Ajisaka
• Reporter: Akira Ajisaka
• Created: 05/Jan/15 18:49
• Updated: 30/Aug/16 01:28
• Resolved: 01/May/15 23:48

Description

When executing manual failover with automatic failover enabled, UnsupportedOperationException is thrown.

# yarn rmadmin -failover rm1 rm2
Exception in thread "main" java.lang.UnsupportedOperationException: RMHAServiceTarget doesn't have a corresponding ZKFC address
	at org.apache.hadoop.yarn.client.RMHAServiceTarget.getZKFCAddress(RMHAServiceTarget.java:51)
	at org.apache.hadoop.ha.HAServiceTarget.getZKFCProxy(HAServiceTarget.java:94)
	at org.apache.hadoop.ha.HAAdmin.gracefulFailoverThroughZKFCs(HAAdmin.java:311)
	at org.apache.hadoop.ha.HAAdmin.failover(HAAdmin.java:282)
	at org.apache.hadoop.ha.HAAdmin.runCmd(HAAdmin.java:449)
	at org.apache.hadoop.ha.HAAdmin.run(HAAdmin.java:378)
	at org.apache.hadoop.yarn.client.cli.RMAdminCLI.run(RMAdminCLI.java:482)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
	at org.apache.hadoop.yarn.client.cli.RMAdminCLI.main(RMAdminCLI.java:622)

I'm thinking the above message is confusing to users. (Users may think whether ZKFC is configured correctly...) The command should output error message to stderr instead of throwing Exception.

Issue Links

• is related to: YARN-1177 Support automatic failover using ZKFC
• relates to: YARN-3705 forcemanual transitionToStandby in RM-HA automatic-failover mode should change elector state