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https://issues.apache.org/jira/browse/ROCKETMQ-67?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16030572#comment-16030572
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dongeforever commented on ROCKETMQ-67:
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[~Jaskey] yeah, it had been merged. you could check the comment upstairs
> Consistent Hash allocate strategy support
> -----------------------------------------
>
> Key: ROCKETMQ-67
> URL: https://issues.apache.org/jira/browse/ROCKETMQ-67
> Project: Apache RocketMQ
> Issue Type: New Feature
> Components: rocketmq-client
> Reporter: Jaskey Lam
> Assignee: Jaskey Lam
> Fix For: 4.1.0-incubating
>
>
> For now, the average allocate strategy is very sensitive when clients
> register and unrigister.
> A Consistent Hash allocate strategy option is valueable for the developers
> who care more about latency stabilization and messages duplication.
> Intentions:
> The default AllocateMessageQueueStrategy is averaging strategy which allocate
> queue to consumer as evenly as possible. 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.
> Consistent Hash strategy to allocate queue is a good choice for these users.
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