[HDFS-14435] ObserverReadProxyProvider is unable to properly fetch HAState from Standby NNs

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0
• Fix Version/s: 3.3.0
• Component/s: ha, nn
• Hadoop Flags: Reviewed
• Assignee: Erik Krogen Assign to me
• Reporter: Erik Krogen
• Created: 17/Apr/19 18:06
• Updated: 22/Apr/19 21:24
• Resolved: 22/Apr/19 20:30

Description

We have been seeing issues during testing of the Consistent Read from Standby feature that indicate that ORPP is unable to call getHAServiceState on Standby NNs, as they are rejected with a StandbyException. Upon further investigation, we realized that although the Standby allows the getHAServiceState() call, reading a delegation token is not allowed in Standby state, thus the call will fail when using DT-based authentication. This hasn't caused issues in practice, since ORPP assumes that the state is Standby if it is unable to fetch the state, but we should fix the logic to properly handle this scenario.

Issue Links

• is broken by: HDFS-12943 Consistent Reads from Standby Node