We are trying to set up static membership for Kafka consumers to account for container maintenance upgrades. Every once in while containers will be deployed with improvement which can take down consumer app instances in random order. The termination process for upgrade is SIGKILL while creating a duplicate copy of running instance. This causes rebalance when instance leaves the group & joins the group.
Static membership is helpful for such scenarios. I want to know whether group.instance.id should be set up unique to each instance of consumer app ( appname-instance-1, appname-instnace-2 et al.) or it should be unique to consumer group ( similar to consumer group id ie one instance id for entire consumer group)
Is there any other config we need to change from broker side/consumer side for faster re-balancing ?