Wondering if networking should go in here as a subconcept or just go deeper into them in here?

Update: Added Databases and Networks and Protocols and Consensus Mechanisms in here

Concepts | Concept Map

• Networks and protocols (go deeper?)
• Types of distributed systems
• Coordination
• Consistency & Replication
• Databases

What are Distributed Systems?

A distributed system is a collection of autonomous computing elements that appears to its users as a single coherent system

• Opportunity to bring up P2P networks
  • Structured & Unstructured
    • Can bring up Distributed Hash Tables and bring up IPFS
• A network of independent nodes, each representing a “process” talking to each other via messages
• Properties:
  • Concurrent components
  • Message sharing
  • No global clock
  • Potential failure of individual components
• Two ways to prove the correctness of a distributed system
  • Safety: what a system should never do
    • Never returning a false value
  • Liveness: what a system should do
    • Returning some value
• Two ensure correctness, one uses a consensus algorithm
  • Validity: any value decided upon must be proposed by one of the processes
  • Agreement: all non-faulty processes must agree on the same value
    • Safety property. Honest nodes will never decide on different values
  • Termination: all non-faulty nodes eventually decide
    • Liveness property: All nodes eventually decide on a value

CAP Theorem (Can only choose 2)

Achievable properties of any distributed system

• Consistency: Every node provides the most recent state
  • If a node is updated with some value, when a node returns a value, it should return either that value or an up to date value
• Availability: Every node has consistent read and write access
  • Given information; receive information