Clustering library with support for zero-downtime reloading
If server.js is your regular http server (e.g. express), create cluster.js and add:
var recluster = require('recluster'),
path = require('path');
var cluster = recluster(path.join(__dirname, 'server.js'));
cluster.run();
process.on('SIGUSR2', function() {
console.log('Got SIGUSR2, reloading cluster...');
cluster.reload();
});
console.log("spawned cluster, kill -s SIGUSR2", process.pid, "to reload");then run it
node cluster.js
To hot-reload the server, simply run
kill -s SIGUSR2 <cluster_pid>
To find out which of the N (= number of cores by default) worker instances you're running from inside server.js, you can use
process.env.WORKER_ID
which is zero-based i.e. 0 <= WORKER_ID < N
var cluster = recluster(file, opt)
where
Absolute path to the module that defines the server
Number of active workers (default = cores)
Timeout to kill old workers after reload (seconds).
Defaults to 1 second in development, 1 hour in production.
Minimum time between worker respawns when workers die (seconds)
Maximum respawn time (reached via exponential backoff). Set to 0 or undefined to disable exponential backoff.
The returned object has the following methods:
Starts the cluster by running child processes
Hot-reloads new code. some of the children will remain active
for opt.timeout seconds after reload
Terminates the entire cluster and removes all listeners.
