Pointers for distributed vs decentralised:
Some bookmarks to read if you are a distributed systems researcher [1]
- A decentralized system is a subset of a distributed system.
- The primary difference is how/where the “decision” is made and how the information is shared throughout the control nodes in the system.
- Decentralized means that there is no single point where the decision is made.
- Every node makes a decision for it’s own behaviour and the resulting system behaviour is the aggregate response.
- A key characteristic of decentral systems is that typically no single node will have complete system information.
- “Distributed means that the processing is shared across multiple nodes, but the decisions may still be centralized and use complete system knowledge” says coinbase in their blog post
- A scenario to think of:
- Some control algorithms I’ve seen for multiple quad-copter control are purely distributed in that a central over-seer gives optimization problems to each copter to solve then return the solution.
- The over-seer will then issue commands based on the aggregate result.
- Here’s a philosophical question:
- if the over-seer is “voted” into office by the nodes, is it decentralized or centralized?
- I’d have to say decentralized, but it is arguable says MaRi Eagar
- then I tend to ask what is distributed systems?
Keywords that matter
when you start the debate (here central systems are included): [2]
- Points of Failure / Maintenance
- Fault Tolerance / Stability
- Scalability / Max Population
- Ease of development / Creation
- Evolution / Diversity
References: