Cluster

Cluster is an extensible multi-core server manager for node.js.

Installation

$ npm install cluster

Features

zero-downtime restart
hard shutdown support
graceful shutdown support
resuscitates workers
maintains worker count, even if worker was _SIGKILL_ed.
workers commit suicide when master dies
spawns one worker per cpu (by default)
extensible via plugins
bundled plugins
- cli: provides a command-line interface for your cluster
- debug: verbose debugging information
- logger: master / worker logs
- pidfiles: writes master / worker pidfiles
- reload: reloads workers when files change
- repl: perform real-time administration
- stats: adds real-time statistics to the repl plugin
supports node 0.2.x
supports node 0.4.x
supports TCP servers

Example

app.js:

var http = require('http');

module.exports = http.createServer(function(req, res){
  console.log('%s %s', req.method, req.url);
  var body = 'Hello World';
  res.writeHead(200, { 'Content-Length': body.length });
  res.end(body);
});

server.js:

var cluster = require('cluster')
  , app = require('./app');

cluster(app)
  .use(cluster.logger('logs'))
  .use(cluster.stats())
  .use(cluster.pidfiles('pids'))
  .use(cluster.cli())
  .use(cluster.repl(8888))
  .listen(3000);

Note that cluster does not create these directories for you, so you may want to:

$ mkdir {logs,pids}

recommended usage: passing the path to prevent unnecessary database connections in the master process, as ./app is only require()ed within the workers.

var cluster = require('cluster');

cluster('./app')
  .use(cluster.logger('logs'))
  .use(cluster.stats())
  .use(cluster.pidfiles('pids'))
  .use(cluster.cli())
  .use(cluster.repl(8888))
  .listen(3000);

Plugins

Below are the known 3rd-party plugins for cluster:

cluster-log remote logger powered by redis
cluster-mail email exception notifications
cluster-exception extensive exception notifications
cluster-responsetimes response time statistics for cluster's REPL
cluster-vhost add virtual host support to cluster

Screencasts

Cluster Introduction

Running Tests

Install development dependencies:

$ npm install

Then:

$ make test

Actively tested with node:

0.4.9

Authors

TJ Holowaychuk

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

ejmvar/cluster