README.md

goPaxos

goPaxos is an implementation of a single instance of the Paxos consensus algorithm in Go. It is based on the outline given in Paxos Made Simple. The main components of the algorithm - proposers, acceptors and learners - are implemented in their respective packages.

Usage

1. Run make in the src/paxos directory.

> make
go install ./...

2. Add bin/ from the repository to your PATH.
3. Create a configuration file with the host:port information for proposers, acceptors and learners.

> init-config -np 2 -na 3 -nl 2
{
  "Proposers": [
    "localhost:34379",
    "localhost:34380"
  ],
  "Acceptors": [
    "localhost:34381",
    "localhost:34382",
    "localhost:34383"
  ],
  "Learners": [
    "localhost:34384",
    "localhost:34385"
  ]
}

4. Start proposer, acceptors, learners.

> init-proposer &
> init-acceptor &
> init-learner &

Tests

1. Simple: This is the normal case. A proposer proposes a value. All learners should get that value eventually.

> simple
PASS.

2. Concur: Two proposers propose a value concurrently. All learners should get the same value eventually.

> concur
PASS with hello_world2

TODO

• Distinguished Proposer - Use zookeeper for leader election.
• Multi-Paxos - Support for multiple instances of the algorithm to build a replicated state machine.
• Fault Tolerance - Test single/multi paxos with random failures.