RACS-SADL: Robust and understandable randomized consensus in the cloud Tennage, Pasindu Desjardins, Antoine Kokoris Kogias, Eleftherios ; https://orcid.org/0000-0002-8827-3382 Widely deployed consensus protocols in the cloud are often leader-based and optimized for low latency under synchronous network conditions. However, cloud networks can experience disruptions such as network partitions, high-loss links, and configuration errors. These disruptions interfere with the operation of leader-based protocols, as their view change mechanisms interrupt the normal case replication and cause the system to stall. We propose RACS, a novel randomized consensus protocol that ensures robustness against adversarial network conditions. RACS achieves optimal one-round trip latency under synchronous network conditions while remaining resilient to adversarial network conditions. RACS follows a simple design inspired by Raft, the most widely used consensus protocol in the cloud, and therefore enables seamless integration with the existing cloud software stack. Experiments with a prototype running on Amazon EC2 show that RACS achieves 28k cmd/sec throughput, ninefold higher than Raft under adversarial cloud network conditions. Under synchronous network conditions, RACS matches the performance of Multi-Paxos and Raft, achieving a throughput of 200k cmd/sec with a median latency of 300ms, confirming that RACS introduces no unnecessary overhead. Finally, SADL-RACS, a throughput-optimized version of RACS, achieves a throughput of 500k cmd/sec, delivering 150 percent higher throughput than Raft. IEEE 2025 info:eu-repo/semantics/conferenceObject doc-type:conferenceObject text http://purl.org/coar/resource_type/c_5794 https://research-explorer.ista.ac.at/record/21243 Tennage P, Desjardins A, Kokoris Kogias E. RACS-SADL: Robust and understandable randomized consensus in the cloud. In: <i>2025 IEEE 18th International Conference on Cloud Computing</i>. IEEE; 2025. doi:<a href="https://doi.org/10.1109/cloud67622.2025.00044">10.1109/cloud67622.2025.00044</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1109/cloud67622.2025.00044 info:eu-repo/semantics/altIdentifier/e-isbn/9798331555573 info:eu-repo/semantics/altIdentifier/arxiv/2404.04183 info:eu-repo/semantics/openAccess