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Offering a first improvement to Connect's behavior under the above scenarios is the primary motivation of this KIP. 

Proposed Changes

Out of the policies that are listed in Incremental Cooperative Rebalancing, this KIP is proposing an implementation that applies deferred resolution of imbalance (Design II in Incremental Cooperative Rebalancing). This policies policy appears to strike a good balance for a first implementation of Incremental Cooperative Connect protocol, since it aims to help all the aforementioned use cases and keeps imbalance resolution simple across consecutive rebalance rounds. It's worth mentioning here that, compared to other recent approaches that aim to alleviate the symptoms of an expensive rebalancing process basically by avoiding rebalancing altogether (for example see KIP-345), this KIP attempts to make rebalancing significantly lighter, even if that means that, in some cases, the number of actual rebalances increases. Connect provides a good platform for a first implementation of Incremental Cooperative Rebalancing and its reassignment heuristics, because connectors and tasks traditionally do not depend on local state that has to be restored upon restart. The necessary changes changes necessary to implement an incremental and cooperative approach to Connect's rebalance protocol are described in the rest of the section. 

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