You don't gain much by running #4 between broker bounces. Running it after the cluster is upgraded will be sufficient.
Thanks, Neha On Wed, Jun 18, 2014 at 8:33 AM, Yury Ruchin <yuri.ruc...@gmail.com> wrote: > Hi folks, > > In my project, we want to perform to update our active Kafka 0.8 cluster to > Kafka 0.8.1.1 without downtime and losing any data. The process (after > reading http://kafka.apache.org/documentation.html#upgrade) looks to me > like this. For each broker in turn: > > 1. Bring the broker down. > 2. Update Kafka to 0.8.1.1 on the broker node. > 3. Start the broker. > 4. Run preferred-replica-election script to restore broker's leadership for > respective partitions. > 5. Wait for the the preferred replica election to complete. > > I deem step#5 necessary since preferred replica election is an asynchronous > process. There is a slim chance that bringing other brokers down before the > election is complete would result in all replicas down for some partitions, > so a portion of the incoming data stream would be lost. Is my understanding > of the process correct? >
