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arXiv · 2501.00021

Did we miss P In CAP? Partial Progress Conjecture under Asynchrony

Junchao Chen·Suyash Gupta·Daniel P. Hughes·Mohammad Sadoghi
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Abstract

Each application developer desires to provide its users with consistent results and an always-available system despite failures. Boldly, the CALM theorem disagrees. It states that it is hard to design a system that is both consistent and available under network partitions; select at most two out of these three properties. One possible solution is to design coordination-free monotonic applications. However, a majority of real-world applications require coordination. We resolve this dilemma by conjecturing that partial progress is possible under network partitions. This partial progress ensures the system appears responsive to a subset of clients and achieves non-zero throughput during failures. To this extent, we present the design of our CASSANDRA consensus protocol that allows partitioned replicas to order client requests.

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Junchao Chen, Suyash Gupta, Daniel P. Hughes, Mohammad Sadoghi. 2024-12-16. Did we miss P In CAP? Partial Progress Conjecture under Asynchrony. https://arxiv.org/abs/2501.00021

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