I'm working on trying on having seamless rolling restarts for my kafka servers, running 0.8. I have it so that each server will be restarted sequentially. Each server takes itself out of the load balancer (e.g. sets a status that the lb will recognize, and then waits more than long enough for the lb to stop sending meta-data requests to that server). Then I initiate the shutdown (with controlled.shutdown.enable=true). This seems to work well, however, I occasionally see warnings like this in the log from the server, after restart:
2013-06-23 08:28:46,770 WARN [kafka-request-handler-2] server.KafkaApis - [KafkaApi-508818741] Produce request with correlation id 7136261 from client on partition [mytopic,0] failed due to Leader not local for partition [mytopic,0] on broker 508818741 This WARN seems to persistently repeat, until the producer client initiates a new meta-data request (e.g. every 10 minutes, by default). However, the producer doesn't log any errors/exceptions when the server is logging this WARN. What's happening here? Is the message silently being forwarded on to the correct leader for the partition? Is the message dropped? Are these WARNS particularly useful? Thanks, Jason