>>>>>> what my doubt is from documentation if namenode maintains an persistent >>>>>> session and the created node will not be deleted and how will it trigger >>>>>> standby namenode"
HDFS community is the right place to query this doubt. As I know NN uses ephemeral znodes to handle machine crashes and triggers watch event for switching standby to active. Regards, Rakesh -----Original Message----- From: mufc_fan [mailto:[email protected]] Sent: 18 August 2014 14:39 To: [email protected] Subject: RE: zookeeper in hadoop thank u for ur response...I have one doubt..In name node high availability, from documentation, it states that "each of the NameNode machines in the cluster maintains a persistent session in ZooKeeper. If the machine crashes, the ZooKeeper session will expire, notifying the other NameNode that a failover should be triggered" According to my knowledge "if namenode creates an ephemeral node in zookeeper, when the machine crashes the node gets delete which triggers the watch event so that standby name node creates new ephemeral seesion with zookeeper and becomes new namenode". what my doubt is from documentation if namenode maintains an persistent session and the created node will not be deleted and how will it trigger standby namenode" -- View this message in context: http://zookeeper-user.578899.n2.nabble.com/zookeeper-in-hadoop-tp7580179p7580184.html Sent from the zookeeper-user mailing list archive at Nabble.com.
