The Paxos Algorithm

Learn about the Paxos algorithm, a distributed consensus protocol that enables nodes to agree on a single value, discussing its roles, message types, and limitations, exploring its applications in distributed systems and variants.

Key takeaways
  • Paxos algorithm aims to reach a single consensus on a value.
  • Some entities will have to change their mind to reach consensus.
  • Paxos can reach consensus with exponential backoff.
  • Paxos nodes receive proposals in different orders and have to ignore requests with lower IDs.
  • Paxos nodes can take multiple roles, including proposer, acceptor, and learner.
  • Learners learn the agreed-upon value after consensus is reached.
  • Paxos algorithm has three roles: proposer, acceptor, and learner.
  • Proposers propose values and send prepare and accept messages.
  • Acceptors promise to ignore requests with lower IDs and reply with promise messages.
  • Learners receive accept messages and figure out the consensus value.
  • Paxos ensures that all nodes agree on the same value.
  • Paxos is useful for distributed systems, such as a distributed storage system.
  • Paxos has limitations, including potential hotspots and contentious proposals.
  • Paxos nodes must know how many acceptors are required for a majority.
  • Paxos nodes are responsible for reaching consensus and learning the final value.
  • Paxos algorithm is used to reach consensus in a distributed system.
  • Distributed systems rely on algorithms to reach consensus, such as Paxos.
  • Paxos ensures that changes to an entity are eventually perceived by all nodes.
  • Paxos has a family of variants that can deal with different scenarios.
  • Paxos is used in a storage system that involves proposals and acceptances.