Redlock-leader NPM

Redlock Leader

Leader election by Redlock Distributed Lock Manager algorithm.

Install

npm install redlock-leader

Usage

const RedlockLeader = require('redlock-leader');
const client = require('redis').createClient({
  host: process.env.REDIS_HOST || '127.0.0.1',
  port: 6379,
  enable_offline_queue: false,
  //password: '',
  //db: 1,
  retry_strategy: function (options) {
    return Math.min(options.attempt * 100, 3000);
  }
});

const leader = new RedlockLeader({
  clients: [client], {
    ttl: 10000,
    wait: 1000,
    key: 'my-leader-key'
}});

leader.on('elected', () => console.log(`${process.pid} ${new Date()} Instance is elected as leader.`));
leader.on('revoked', () => console.log(`${process.pid} ${new Date()} Instance is no longer the leader.`));
leader.on('extended', () => console.log(`${process.pid} ${new Date()} Leadership status of instance is extended.
`));
leader.on('error', (e) => console.log(`${process.pid} ${new Date()} ERROR`, e));

leader.start();

API

new RedlockLeader(clients, options)

Create a new leader selector.

clients An array of redis client instances.
options An object holding the leader selection options.
- ttl Lock time to live in milliseconds, defaults to 10000 milliseconds.
- wait Time between 2 tries getting elected in milliseconds, defaults to 1000 milliseconds
- key A string key identifying the lock, defaults to 'redlock-leader'