https://github.com/kanaka/raft.js

Raft.js is an implementation of the Raft consensus algorithm in JavaScript and using WebRTC.
https://github.com/kanaka/raft.js

Last synced: 26 days ago
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Raft.js is an implementation of the Raft consensus algorithm in JavaScript and using WebRTC.

• Host: GitHub
• URL: https://github.com/kanaka/raft.js
• Owner: kanaka
• License: mpl-2.0
• Created: 2013-09-16T21:19:10.000Z (about 11 years ago)
• Default Branch: master
• Last Pushed: 2020-09-28T21:23:44.000Z (about 4 years ago)
• Last Synced: 2024-09-16T08:51:30.219Z (about 2 months ago)
• Language: TeX
• Homepage:
• Size: 18.3 MB
• Stars: 319
• Watchers: 15
• Forks: 32
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

Awesome Lists containing this project

• awesome-javascript - raftjs
• awesome-javascript - raftjs

README

        
# Raft.js: Raft Consensus Algorithm in JavaScript

Raft.js is an implementation of [The Raft Consensus

Algorithm](http://raftconsensus.github.io/) in JavaScript. The Raft

algorithm was developed by Diego Ongaro and John Ousterhout at

Stanford University. Please refer to their excellent paper on Raft:

["In Search of an Understandable Consensus

Algorithm"](https://raft.github.io/raft.pdf).

## Example

Start a node REPL and require one of the test modules.

    > t = require('./test_local');

    # OR

    > t = require('./test_http');

The local test module starts servers in the same process that

communicate directly with function calls. The http test creates

servers in the same process but they communicate with each other by

sending messages over HTTP.

Start 3 servers (an optional second argument specifies the number of

servers to start):

    > t.startServers({debug:true});

Get the leader ID and show its entry log:

    > lid = t.getLeaderId();

    > t.getAll('log')[lid];

Set a key/value in the state machine, show the log and

stateMachine for all the servers, then read back the value:

    > t.serverPool[lid].clientRequest({op:"set",key:'a',value:1}, function(results) { console.log("results: ", results); });

    > t.getAll('log');

    > t.getAll('stateMachine');

    > t.serverPool[lid].clientRequest({op:"get",key:'a',ro:1}, function(results) { console.log("results: ", results); });

Add a new server (ID 3), set a different value and show that it

has propagated to all the server state machines:

    > t.addServer(3,{debug:true});

    > t.serverPool[lid].clientRequest({op:"set",key:'b',value:2}, function(results) { console.log("results: ", results); });

    > t.getAll('stateMachine');

## Status

The following features have been implemented (the section number of

the Raft paper is listed in brackets):

* [5.2] Leader election

* [5.3] Log replication and persistence

* [5.4, 5.5, 5.6, 5.7] Safety features

* [7.1] Client interaction (except filtering duplicates)

* [5.1] RPCs:

 * In-process (direct function calls) for quick testing

 * Over HTTP

* [6] Membership change / joint consensus

## TODO

* [7.1] filter duplicate client requests

* [7.2] log compaction

* faster resend of appendEntries when follower responds with fail

  (nextIndex update)

* faster re-issue of requestVote to non-responders

* more exception handling

* in depth testing

## License

Licensed under [MPL-2.0](http://www.mozilla.org/MPL/2.0/). See

LICENSE.txt.