[HDFS-8161] Both Namenodes are in standby State

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.6.0
• Component/s: auto-failover
• Assignee: Brahma Reddy Battula
• Reporter: Brahma Reddy Battula
• Created: 16/Apr/15 15:23
• Updated: 17/Aug/16 04:06

Description

Suspected Scenario:
================
Start cluster with three Nodes.
Reboot Machine where ZKFC is not running..( Here Active Node ZKFC should open session with this ZK )

Now ZKFC ( Active NN's ) session expire and try re-establish connection with another ZK...Bythe time ZKFC ( StndBy NN's ) will try to fence old active and create the active Breadcrumb and Makes SNN to active state..

But immediately it fence to standby state.. ( Here is the doubt)

Hence both will be in standby state..

Issue Links

• duplicates: HDFS-8221 HDFS have two Standby NNs because ActiveStandbyElectorLock ephemeralOwner in ZK is different with the sessionId stored in ZKFC
• is related to: ZOOKEEPER-2175 Checksum validation for malformed packets needs to handle.