Ensuring fault tolerance and identifying failures in a key-value store

In this section, we will explore how to construct a fault-tolerant key-value store capable of identifying and managing system failures. Let’s begin with the techniques to manage temporary failures, ensuring that our key-value store can weather short-term disturbances or disruptions.

Managing temporary failures

A common approach to dealing with failures in distributed systems is the use of a quorum-based system. A quorum refers to the minimum number of votes that a distributed transaction needs to carry out an operation. If a server that is part of the consensus goes down, the operation cannot proceed, impacting a system’s availability and durability.

Instead of relying on strict quorum membership, we propose using a sloppy quorum. In most cases, a central leader coordinates communication between consensus participants. After a successful write, participants send an acknowledgment. The leader...