This is a continuation of the earlier posts starting with this one: http://ravinote.blogspot.com/2020/09/best-practice-from-networking.html  

The consensus protocol used in distributed components of a storage system, is required to be fault-tolerant. However, the choice of consensus protocol may vary from system to system

Message passing between agents in a distributed environment is required. Any kind of protocol can suffice for this. Some  systems like to use open source in this regard while others build on message queuing.

Every networking server prepares for fault tolerance. Since faults can occur in any domain, temporarily or permanently, each component determines which activities to perform and how to overcome what is not available.

Fault domains are a group covering known faults in an isolation. Yet some faults may occur in combinations. It is best to give names to patterns of faults so that they can be included in the design of components.

Data driven computing has required changes in networking products. While previously, online transactional activities were read-write intensive and synchronous, today most processors including order and payments are done asynchronously on data driven frameworks usually employing a message queueing. Networking products do better with improved caching for these processing 

#codingexercise: https://ideone.com/DBjnkH