Just to be clear, I'm not asking that we solve "duplicate messages on crash before commit to Zookeeper", just an apparent problem where if Kafka has some data, and we start on ConsumerConnectors, we get dupe data since some Consumers come up before others.
Any help? Philip On Thu, Jun 13, 2013 at 7:34 PM, Philip O'Toole <phi...@loggly.com> 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
