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Kafka, mail # user - 0.8 best practices for migrating / electing leaders in failure situations?


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Scott Clasen 2013-03-22, 17:47
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Neha Narkhede 2013-03-22, 20:13
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Scott Clasen 2013-03-22, 21:17
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Neha Narkhede 2013-03-22, 22:22
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Jun Rao 2013-03-23, 04:15
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Scott Clasen 2013-03-23, 04:23
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Re: 0.8 best practices for migrating / electing leaders in failure situations?
Jun Rao 2013-03-24, 23:01
If you bring up 3 new brokers with different broker ids, you won't be able
to use them on existing topics until after you have run the partition
reassignment tool.

Thanks,

Jun

On Fri, Mar 22, 2013 at 9:23 PM, Scott Clasen <[EMAIL PROTECTED]> wrote:

> Thanks!
>
>  Would there be any difference if I instead  deleted all the Kafka data
> from zookeeper and booted 3 instances  with different broker id? clients
> with cached broker id lists or any other issue?
>
> Sent from my iPhone
>
> On Mar 22, 2013, at 9:15 PM, Jun Rao <[EMAIL PROTECTED]> wrote:
>
> > In scenario 2, you can bring up 3 new brokers with the same broker id.
> You
> > won't get the data back. However, new data can be published to and
> consumed
> > from the new brokers.
> >
> > Thanks,
> >
> > Jun
> >
> > On Fri, Mar 22, 2013 at 2:17 PM, Scott Clasen <[EMAIL PROTECTED]> wrote:
> >
> >> Thanks Neha-
> >>
> >> To Clarify...
> >>
> >> *In scenario => 1 will the new broker get all messages on the other
> brokers
> >> replicated to it?
> >>
> >> *In Scenario 2 => it is clear that the data is gone, but I still need
> >> producers to be able to send and consumers to receive on the same
> topic. In
> >> my testing today I was unable to do that as I kept getting errors...so
> if i
> >> was doing the correct steps it seems there is a bug here, basically the
> >> "second-cluster-topic" topic is unusable after all 3 brokers crash, and
> 3
> >> more are booted to replace them.  Something not quite correct in
> zookeeper?
> >>
> >> Like so
> >>
> >> ./bin/kafka-reassign-partitions.sh --zookeeper ... --path-to-json-file
> >> reassign.json
> >>
> >> kafka.common.LeaderNotAvailableException: Leader not available for topic
> >> second-cluster-topic partition 0
> >> at kafka.admin.AdminUtils$$anonfun$3.apply(AdminUtils.scala:120)
> >> at kafka.admin.AdminUtils$$anonfun$3.apply(AdminUtils.scala:103)
> >> at
> >>
> >>
> scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:206)
> >> at
> >>
> >>
> scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:206)
> >> at
> >>
> >>
> scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61)
> >> at scala.collection.immutable.List.foreach(List.scala:45)
> >> at scala.collection.TraversableLike$class.map(TraversableLike.scala:206)
> >> at scala.collection.immutable.List.map(List.scala:45)
> >> at
> >>
> >>
> kafka.admin.AdminUtils$.kafka$admin$AdminUtils$$fetchTopicMetadataFromZk(AdminUtils.scala:103)
> >> at kafka.admin.AdminUtils$.fetchTopicMetadataFromZk(AdminUtils.scala:92)
> >> at kafka.admin.ListTopicCommand$.showTopic(ListTopicCommand.scala:80)
> >> at
> >>
> >>
> kafka.admin.ListTopicCommand$$anonfun$main$2.apply(ListTopicCommand.scala:66)
> >> at
> >>
> >>
> kafka.admin.ListTopicCommand$$anonfun$main$2.apply(ListTopicCommand.scala:65)
> >> at
> >>
> >>
> scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61)
> >> at scala.collection.immutable.List.foreach(List.scala:45)
> >> at kafka.admin.ListTopicCommand$.main(ListTopicCommand.scala:65)
> >> at kafka.admin.ListTopicCommand.main(ListTopicCommand.scala)
> >> Caused by: kafka.common.LeaderNotAvailableException: No leader exists
> for
> >> partition 0
> >> at kafka.admin.AdminUtils$$anonfun$3.apply(AdminUtils.scala:117)
> >> ... 16 more
> >> topic: second-cluster-topic
> >>
> >> ./bin/kafka-preferred-replica-election.sh  --zookeeper...
> >> --path-to-json-file elect.json
> >>
> >>
> >> ....[2013-03-22 10:24:20,706] INFO Created preferred replica election
> path
> >> with { "partitions":[ { "partition":0, "topic":"first-cluster-topic" },
> {
> >> "partition":0, "topic":"second-cluster-topic" } ], "version":1 }
> >> (kafka.admin.PreferredReplicaLeaderElectionCommand$)
> >>
> >> ./bin/kafka-list-topic.sh  --zookeeper ... --topic second-cluster-topic
> >>
> >> 2013-03-22 10:24:30,869] ERROR Error while fetching metadata for
> partition
> >> [second-cluster-topic,0] (kafka.admin.AdminUtils$)
> >> kafka.common.LeaderNotAvailableException: Leader not available for topic

 
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Scott Clasen 2013-03-25, 16:58
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Neha Narkhede 2013-03-26, 00:37
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Jun Rao 2013-03-26, 04:35