The Journey of a Request in a Raft-Based KV Store"

Originally published on: https://abdellani.dev/posts/2026-04-01-the-journey-of-a-request-in-a-raft-based-kv-store/ Introduction: This article comes after implementing labs 3 and 4 from the open MIT 6.584 course. We have a replicated KV server on top of the RAFT protocol, and we want to understand how the server works internally. To do so, I propose to follow all the steps that a request will pass through on the server before a client receives a response. The objective of building the KV server on top of the RAFT protocol is to have a fault-tolerant system. The system is composed of multiple KV server nodes, if some servers fall down, the system should continue serving the clients. Raft is strongly consistent and can tolerate the failure of f nodes in a system composed of 2 * f + 1 nodes. For example, if we want the system to tolerate the failure of 2 nodes, we’ll need 5 nodes. The labs are testing the implementation under different conditions: an unreliable network that drops packets o