Hello Oleksiy, All offsets for given consumer group are stored in (and fetched from) one and only one partition of all partitions of __consumer_offsets topic. By default __consumer_offsets has 50 partitions and for each of these partitions replication factor is 3, so there is one lead and 2 extra replicas.
If I'm not mistaken, offset/group coordinator for a given consumer group lives on a broker in Kafka cluster which is lead for __consumer_offsets topic partition used for offsets of that consumer group. So your question is I guess equivalent to question - can a different broker become a lead for a partition, for which answer is yes, as long as there are alive replicas for that partition. Kind regards, Stevo Slavic. On Sat, Jan 9, 2016 at 4:23 PM, Oleksiy Krivoshey <oleks...@gmail.com> wrote: > Hi! > > Is it possible for the group coordinator for the same group to change from > one host to some other during cluster runtime? For example when the host > that used to be the coordinator is down - can Kafka cluster choose new > coordinator for the group? Or is it fixed? > > Thanks! >
