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lvchuanwen commented on HADOOP-10251: ------------------------------------- yes .hadoop-deamon.sh start namenode nn1 then kill nn2 ,nn1 can transition to active > Both NameNodes could be in STANDBY State if SNN network is unstable > ------------------------------------------------------------------- > > Key: HADOOP-10251 > URL: https://issues.apache.org/jira/browse/HADOOP-10251 > Project: Hadoop Common > Issue Type: Bug > Components: ha > Affects Versions: 2.2.0 > Reporter: Vinayakumar B > Assignee: Vinayakumar B > Priority: Critical > Fix For: 2.5.0 > > Attachments: HADOOP-10251.patch, HADOOP-10251.patch, > HADOOP-10251.patch, HADOOP-10251.patch, HADOOP-10251.patch > > > Following corner scenario happened in one of our cluster. > 1. NN1 was Active and NN2 was Standby > 2. NN2 machine's network was slow > 3. NN1 got shutdown. > 4. NN2 ZKFC got the notification and trying to check for old active for > fencing. (This took little more time, again due to slow network) > 5. In between, NN1 got restarted by our automatic monitoring, and ZKFC made > it Active. > 6. Now NN2 ZKFC got Old Active as NN1 and it did graceful fencing of NN1 to > STANBY. > 7. Before writing ActiveBreadCrumb to ZK, NN2 ZKFC got session timeout and > got shutdown before making NN2 Active. > *Now cluster having both NameNodes as STANDBY.* > NN1 ZKFC still thinks that its nameNode is in Active state. > NN2 ZKFC waiting for election. -- This message was sent by Atlassian JIRA (v6.3.4#6332)