Hi Richard, You are correct that version will now be 0.9.0 and anything referencing 0.8.3 is being changed. You are also correct in the there have been wire protocol changes that break compatibility. However, backwards compatibility exists and you should always upgrade your brokers before upgrading your clients in order to avoid issues (In the future KIP-35 <http://KIP-35+-+Retrieving+protocol+version> may change that).
It's also worth noting that if you are performing a rolling upgrade of your brokers, you need to be sure brokers running the new protocol know to communicate with the old version to remain compatible during the bounce. This is done using the inter.broker.protocol.version property. More on that topic can be read here: https://kafka.apache.org/083/documentation.html#upgrade Hopefully that helps clear things up. Thank you, Grant On Thu, Oct 1, 2015 at 12:21 PM, Richard Lee <rd...@tivo.com> wrote: > Note the 0.8.3-SNAPSHOT has recently been renamed 0.9.0.0-SNAPSHOT. > > In any event, the major version number change could indicate that there > has, in fact, been some sort of incompatible change. Using 0.9.0.0, I'm > also unable to use the kafka-console-consumer.sh to read from a 0.8.2.1 > broker, but it works fine with a 0.9.0.0 broker. > > Some validation from a kafka expert that broker forward compatibility (or > client backward compatibility) is not supported would be appreciated, and > that this isn't just a case of some sort of local, fixable misconfiguration. > > Thanks! > Richard > > On 09/30/2015 11:17 AM, Doug Tomm wrote: > >> hello, >> >> i've got a set of broker nodes running 0.8.2.1. on my laptop i'm also >> running 0.8.2.1, and i have a single broker node and mirrormaker there. >> i'm also using kafka-console-consumer.sh on the mac to display messages on >> a favorite topic being published from the broker nodes. there are no >> messages on the topic, but everything is well-behaved. i can inject >> messages with kafkacat and everything is fine. >> >> but then! >> >> on the laptop i switched everything to 0.8.3 but left the broker nodes >> alone. now when i run mirrormaker i see this: >> >> [2015-09-30 10:44:55,090] WARN >> [ConsumerFetcherThread-tivo_kafka_110339-mbpr.local-1443635093396-c55cbafb-0-5], >> Error in fetch kafka.consumer.ConsumerFetcherThread$FetchRequest@61cb11c5. >> Possible cause: java.nio.BufferUnderflowException >> (kafka.consumer.ConsumerFetcherThread) >> [2015-09-30 10:44:55,624] WARN >> [ConsumerFetcherThread-tivo_kafka_110339-mbpr.local-1443635093396-c55cbafb-0-5], >> Error in fetch kafka.consumer.ConsumerFetcherThread$FetchRequest@3c7bb986. >> Possible cause: java.nio.BufferUnderflowException >> (kafka.consumer.ConsumerFetcherThread) >> [2015-09-30 10:44:56,181] WARN >> [ConsumerFetcherThread-tivo_kafka_110339-mbpr.local-1443635093396-c55cbafb-0-5], >> Error in fetch kafka.consumer.ConsumerFetcherThread$FetchRequest@1d4fbd2c. >> Possible cause: java.nio.BufferUnderflowException >> (kafka.consumer.ConsumerFetcherThread) >> [2015-09-30 10:44:56,726] WARN >> [ConsumerFetcherThread-tivo_kafka_110339-mbpr.local-1443635093396-c55cbafb-0-5], >> Error in fetch kafka.consumer.ConsumerFetcherThread$FetchRequest@59e67b2f. >> Possible cause: java.nio.BufferUnderflowException >> (kafka.consumer.ConsumerFetcherThread) >> >> if i use kafkacat to generate a message on the topic i see >> IllegalArgumentExceptions instead. >> >> this suggests that the two versions of kafka aren't compatible. is this >> the case? does the whole ecosystem need to be on the same version? >> >> thank you, >> doug >> >> > -- Grant Henke Software Engineer | Cloudera gr...@cloudera.com | twitter.com/gchenke | linkedin.com/in/granthenke
