cluster-key-slot

What is cluster-key-slot?

The cluster-key-slot npm package is designed for calculating the hash slot for a given key in a Redis Cluster. This is crucial for applications that interact with Redis Clusters, as it allows them to determine which node in the cluster is responsible for a given key. By doing so, it enables efficient data access and manipulation within a distributed Redis environment.

What are cluster-key-slot's main functionalities?

Calculate hash slot for a key

This feature allows you to calculate the hash slot for a given key. The code sample demonstrates how to import the cluster-key-slot package, use it to calculate the hash slot for the key 'myKey', and then log the result. This is useful for determining which node in a Redis Cluster will handle the key.

"use strict";
const calculateSlot = require('cluster-key-slot');
const slot = calculateSlot('myKey');
console.log(slot);

Other packages similar to cluster-key-slot

ioredis

ioredis is a robust, performance-focused, and full-featured Redis client for Node.js. It supports Redis Cluster out of the box, including automatic partitioning of commands across the cluster. While cluster-key-slot focuses solely on calculating hash slots, ioredis provides a comprehensive solution for interacting with Redis, including cluster support, which inherently deals with hash slots as part of its functionality.

redis-clustr

redis-clustr is a Redis client for Node.js with support for clustering. It provides transparent command routing to the correct Redis node in a cluster, based on the key's hash slot. Unlike cluster-key-slot, which is a utility for calculating hash slots, redis-clustr is a full client that manages connections and commands within a Redis Cluster, including the calculation and handling of hash slots.

README

cluster-key-slot

A high performance cluster key slot calculator for node redis clients e.g. node_redis and ioredis.

This also handles key tags such as somekey{actualTag}.

Install

Install with NPM:

npm install cluster-key-slot --save

Usage

const calculateSlot = require('cluster-key-slot');
const calculateMultipleSlots = require('cluster-key-slot').generateMulti;

// ...

// a single slot number
const slot = calculateSlot('test:key:{butOnlyThis}redis');

// multiple keys - multi returns a single key slot number, returns -1 if any
// of the keys does not match the base slot number (base is defaulted to first keys slot)
// This is useful to quickly determine a singe slot for multi keys operations.
const slotForRedisMulti = calculateMultipleSlots([
  'test:key:{butOnlyThis}redis',
  'something:key45:{butOnlyThis}hello',
  'example:key46:{butOnlyThis}foobar',
]);

Benchmarks

OLD in these benchmarks refers to the ioredis crc calc and many of the other calculators that use Buffer.

NEW tags x 482,204 ops/sec ±1.07% (87 runs sampled)
OLD tags x 204,380 ops/sec ±1.51% (85 runs sampled)
NEW without tags x 1,250,274 ops/sec ±1.30% (87 runs sampled)
OLD without tags x 266,518 ops/sec ±1.29% (87 runs sampled)
NEW without tags singular x 3,617,430 ops/sec ±1.03% (85 runs sampled)
OLD without tags singular x 1,223,707 ops/sec ±1.15% (86 runs sampled)