High availability

Number of servers

The recommended number of servers is 3 to 7 to balance between latency and availability. This recommendation aligns with the principles of the Raft consensus algorithm, which is designed to manage a replicated log across multiple servers.

In Raft, having an odd number of servers (typically 3, 5, or 7) is preferred to ensure that a majority can be reached for consensus. This majority is crucial for maintaining data consistency and fault tolerance. With 3 to 7 servers, the system can tolerate up to 1 or 3 server failures respectively, while still maintaining availability and ensuring that the remaining servers can continue to operate and reach consensus.

Raft parameters

The Raft parameters, such as heartbeat timeout and election timeout, can be tuned to accommodate different scenarios. Adjusting these parameters allows for optimization based on network conditions and server performance, ensuring efficient leader election and stable cluster operation.