Definition of Rachis: Spinal column, also the distal part of the shaft of a feather that bears the web.
What is Raft ?
Raft is a simple and easy-to-understand distributed consensus protocol.
It allows you to execute an ordered set of operations across your entire cluster.
This means that you can apply a set of operations on a state machine, and have the same final state machine in all the cluster's nodes.
So any series of events (called a Raft Commands) will be executed in the same order on each node.
The Leader Node accepts all the Raft Commands requests for the cluster and handles committing them cluster-wide.
These Raft Commands are done only if the majority of the nodes in the cluster agreed to it !