is-cluster-master
This module finds the master node instance in a cluster by inserting the nodes in a Redis and choosing the master by which node is the oldest. Each node checks into redis on a set timeout (default 60 seconds). If the master node dies, redis will expire the record. Ioredis and Redis is REQUIRED for work.
Installation
npm i is-cluster-master
Usage
Use keyPrefix parameter of IORedis connection!
const Redis = require('ioredis');
const NodeCluster = require('is-cluster-master');
const redis = new Redis(6379, 'localhost', {
keyPrefix: 'node-',
});
const master = new NodeCluster({
redis,
keyPrefix: 'node-',
timeout: 60,
});
master.on('Changed', function() {
console.log('The master variable has changed');
});
master.on('master', function() {
console.log('The process has been promoted to master');
});
master.on('slave', function(){
console.log('The process has been demoted to slave');
});
console.log(master.isMaster());
Options
When starting the worker, you can specify options in an object to update the default values.
new NodeCluster({
timeout: 120, // How often the nodes check. In seconds, default 60.
keyPrefix: 'node', // Prefix using in redis connection, default 'node-'.
redis: new Redis({...}), // IORedis connection
});
Contributing
- Fork it!
- Create your feature branch:
git checkout -b my-new-feature - Commit your changes:
git commit -am 'Add some feature' - Push to the branch:
git push origin my-new-feature - Submit a pull request :D
History
- 1.0.0 Initial release