Hi Team, Could you please help to understand those features?
Thanks, Yogesh Sangvikar On Tue, Jun 18, 2013 at 6:55 PM, Yogesh Sangvikar < yogesh.sangvi...@gmail.com> wrote: > Hi Team, > > I am exploring kafka 0.8 beta release to understand data flow, replication > features. > While testing i found that, the partition data for data for deleted topic > is preseved in kafka-logs, why this behavior? suppose below case, > > A topic (suppose test1) is created with partition 6 and replication 3 on > a system with 4 brokers, respective log and index files will be prepared > per partition in kafka-logs. If I delete the topic and recreate the same > topic ‘test1’ after some time with partition 2 and replication 2. The > kafka-logs directory seems to be confusing to understand why the partitions > for previous topic are present. *Please help to understand this scenario*. > > Also, while testing the replication and leader selection feature observed > leader -1 status, > > Original status: > topic: test1 partition: 0 leader: 4 replicas: 4,2,3 isr: 4,2,3 > topic: test1 partition: 1 leader: 0 replicas: 0,3,4 isr: 0,3,4 > topic: test1 partition: 2 leader: 1 replicas: 1,4,0 isr: 1,4,0 > if leader 4 goes down: > topic: test1 partition: 0 leader: 2 replicas: 4,2,3 isr: 2,3 > topic: test1 partition: 1 leader: 0 replicas: 0,3,4 isr: 0,3,4 > topic: test1 partition: 2 leader: 1 replicas: 1,4,0 isr: 1,0,4 > > if leader 2 goes down: > topic: test1 partition: 0 leader: 3 replicas: 4,2,3 isr: 3 > topic: test1 partition: 1 leader: 0 replicas: 0,3,4 isr: 0,3,4 > topic: test1 partition: 2 leader: 1 replicas: 1,4,0 isr: 1,0,4 > > if again leader 3 goes down: > topic: test1 partition: 0 leader: -1 replicas: 4,2,3 isr: > topic: test1 partition: 1 leader: 0 replicas: 0,3,4 isr: 0,4 > topic: test1 partition: 2 leader: 1 replicas: 1,4,0 isr: 1,0,4 > > As per kafka protocol guide, *leader: -1 means If no leader exists > because we are in the middle of a leader election this id will be -1.* > > *Does it mean that, the data from partition 0 will be unavailable due no > leader (leader selection in progress)?* > As per my understanding, can we have auto re-balancer facility to > re-balance the partition replications to available brokers if one of the > broker is down, as in above case of (if leader 4 goes down), we can > replicate the partition 0 to broker 0/1 to re-balance the replication. > > Please correct me for any wrong understanding as those are my initial > observations. > > Thanks in advance. > > Thanks, > Yogesh Sangvikar > > >
