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Kafka >> mail # user >> Stall high-level 0.72 ConsumerConnector until all balanced? Avoid message dupes?

Philip OToole 2013-06-14, 02:35
Philip OToole 2013-06-14, 02:57
Jun Rao 2013-06-14, 04:16
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Re: Stall high-level 0.72 ConsumerConnector until all balanced? Avoid message dupes?
Jun -- thanks. We're using 0.72.

No, the messages are not compressed, and since we do appear to be
seeing dupes in our tests, it indicates our own code is buggy.



On Thu, Jun 13, 2013 at 9:15 PM, Jun Rao <[EMAIL PROTECTED]> wrote:
> Are you messages compressed in batches? If so, some dups are expected
> during rebalance. In 0.8, such dups are eliminated. Other than that,
> rebalance shouldn't cause dups since we commit consumed offsets to ZK
> before doing a rebalance.
> Thanks,
> Jun
> On Thu, Jun 13, 2013 at 7:34 PM, Philip O'Toole <[EMAIL PROTECTED]> wrote:
>> Hello -- is it possible for our code to stall a ConsumerConnector from
>> doing any consuming for, say, 30 seconds, until we can be sure that
>> all other ConsumeConnectors are rebalanced?
>> It seems that the first ConsumerConnector to come up is prefetching
>> some data, and we end up with duplicate messages. We looked at the
>> code for the high-level consumer
>> (core/src/main/scala/kafka/consumer/ZookeeperConsumerConnector.scala)
>> and it looks like it empties some queues after a rebalance, but we
>> still see duplicate messages.
>> I'm sure this question has been asked before :-) but this is our first
>> time really working with the high-level consumer, and this caught us
>> by surprise. When there is *no* data in Kafka, wait until everything
>> balances and then send data in everything works fine, but if there is
>> some data sitting in the brokers, we seems to get dupes, even when
>> each thread sleeps for many seconds after creating the
>> ConsumerConnector.
>> Are we missing something?
>> Thanks,
>> Philip

Philip OToole 2013-06-14, 21:05
Jun Rao 2013-06-15, 15:57