A Consistent Hashing C++ add-on for node.js
C++ C JavaScript Python
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Latest commit 38b0069 Apr 21, 2017 @bnoguchi committed on GitHub Merge pull request #18 from jchip/master
Update for Node 4.x.x and up

README.md

node-hash-ring - Consistent Hashing C++ Add-on for node.js


See this blog post for more information.

Installation

Via npm:

$ npm install hash_ring

Via git:

$ git clone http://github.com/bnoguchi/node-hash-ring.git
$ cd node-hash-ring
$ npm run build

Example

var HashRing = require("hash_ring");

// Create a cluster of 3 servers weighted so that 127.0.0.2:8080 stores twice as many 
// keys as 127.0.0.1:8080, and 127.0.0.3:8080 stores 4x as many keys as 127.0.0.1:8080
// and 2x as many keys as 127.0.0.2:8080

var ring = new HashRing({"127.0.0.1:8080": 1, "127.0.0.2:8080": 2, "127.0.0.3:8080":4});
console.log(ring.getNode("users:102") ); // Should be 127.0.0.3:8080

See ./test/test_distribution.js for another example:

$ node test/test_distribution.js

Key Hashing

By default, MD5 is used to hash keys. You can choose another hasher.

var HashRing = require("hash_ring");

var ring = new HashRing({"127.0.0.1:8080": 1, "127.0.0.2:8080": 2, "127.0.0.3:8080":4}, "murmur");

Supported hashers are:

Tests

To run the tests:

$ npm test

License

MIT License


Author

Brian Noguchi