Jaskey opened a new issue #1333: Support Consistent Hash with bounds allocate strategy URL: https://github.com/apache/rocketmq/issues/1333 **FEATURE REQUEST** 1. Please describe the feature you are requesting. As we know, when numbers of consume instances are changed, a 2. Provide any additional detail on your proposed use case for this feature. As we know, the default AllocateMessageQueueStrategy is averaging strategy which allocate queue to consumer as evenly as possible. But whenever queues numbers or consumer numbers changed, say a new consumer starts or an old consumer shutdowns, a rehashing will be triggered then almost all consumer suffered from this that they will rebalance to drop old queues and get new queues. And that will cause message latency from producer to consumer increases at the moment when consumer/queue numbers change, even when they scale up. messages will be duplicated significantly since the offset may not be persisted to broker and that queue is assigned to another consumer to pull messages from. This is especially significant when they have tens of consumer instances and scale-up or deployment is often. https://github.com/apache/rocketmq/pull/67 has provide a Consistent Hash strategy, which is a a good choice for these users. But ConsistentHash is not able to guarantee that the consumer can get an average queue numbers, Maybe we can implement a strategy of Consistent Hash with bounds that can reduce duplication as much as possible as well as ensuring the consumer have the same queues
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