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Kafka >> mail # user >> Partition data for deleted topic found in kafka-logs, also, found leader: -1


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Yogesh Sangvikar 2013-06-18, 13:26
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Yogesh Sangvikar 2013-06-19, 04:42
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Jun Rao 2013-06-19, 15:17
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Re: Partition data for deleted topic found in kafka-logs, also, found leader: -1
Is there a way to manually do this?  Or is there a way to manually change
the replication factor for a topic?  Possibly by manipulating zookeeper
data directly?

Jason
On Wed, Jun 19, 2013 at 8:17 AM, Jun Rao <[EMAIL PROTECTED]> wrote:

> Yogesh,
>
> Delete topic is not supported in 0.8 beta yet. We decided to take this
> feature out in 0.8 beta to make the release available sooner.
>
> Thanks,
>
> Jun
>
>
> On Tue, Jun 18, 2013 at 6:25 AM, Yogesh Sangvikar <
> [EMAIL PROTECTED]> 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
> >
>

 
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Jun Rao 2013-06-20, 04:02