The first replica in the ISR is the preferred replica, but is not required to be the leader at all times. If you execute a preferred leader election, or enable auto.leader.rebalance.enable, then replica 4 will become the leader again.
More can be read here: - http://kafka.apache.org/documentation.html#basic_ops_leader_balancing - https://cwiki.apache.org/confluence/display/KAFKA/Replication+tools#Replicationtools-1.PreferredReplicaLeaderElectionTool Thank you, Grant On Tue, Sep 15, 2015 at 5:26 AM, Prabhjot Bharaj <prabhbha...@gmail.com> wrote: > Hi, > > Topic:part_1_repl_3_3 PartitionCount:1 ReplicationFactor:3 Configs: > > Topic: part_1_repl_3_3 Partition: 0 Leader: 3 Replicas: 3,4,5 Isr: 4,3,5 > > > I see that the replicas are 3,4,5 but, the ISR is 4,3,5. > > > I have this doubt:- > > When the leader is 3, can the ISR be 4, 3, 5 ? > > Does the ISR got to have the leader as the first replica ?? > > > Regards, > > Prabhjot > -- Grant Henke Software Engineer | Cloudera gr...@cloudera.com | twitter.com/gchenke | linkedin.com/in/granthenke
