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

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See this blog post for background on the algorithm.

Installation

Via npm:

npm install @movable/hash_ring

The native addon is compiled on install via node-gyp (invoked automatically), so a C++ toolchain is required.

From source:

git clone https://github.com/movableink/node-hash-ring.git
cd node-hash-ring
npm install

Example

const{ HashRing }=require("@movable/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 127.0.0.2:8080constring=newHashRing({"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 127.0.0.3:8080console.log(ring.getBuckets());// ['127.0.0.1:8080', '127.0.0.2:8080', '127.0.0.3:8080']

An optional second argument controls the number of replica points per bucket (precision):

constring=newHashRing({a: 5,b: 3},500);

TypeScript definitions are bundled (index.d.ts).

Tests

Tests run with mocha:

npm test

License

MIT License

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Author

Brian Noguchi

Maintained by Movable Ink.