Adios

A module for notifying clustered workers for clean shutdowns.

This is accomplished by using domain sockets – /var/run/adios.sock by default – which has the added benefit of not sending messages over application specific IPC channels. This means you don't have to filter out messages from adios in any process.on('message') listeners.

Note: On Windows, the local domain is implemented using a named pipe. The path must refer to an entry in \\?\pipe\ or \\.\pipe\. Therefore, you must initialize adios with a path in this space if you are running on a Windows machine.

Usage

'use strict';
const cluster = require('cluster');
const http = require('http');
const Adios = require('adios');

if (cluster.isMaster) {
  Adios.master.init()
    .then(() => {
      let worker = cluster.fork();
    });
}
else {
  let server = http.createServer();
  Adios.child.init(() => {
    return new Promise(resolve => {
      server.close(resolve);
    });
  })
    .then(() => {
      server.listen(3000);
    });
}

API

• Adios.master.init([path]) - The initialize function for adios masters. Sets up a server for IPC with clustered workers. Note: there can be only one.

  • path - (optional) The socket path to use. Defaults to /var/run/adios.sock
  • config - (optional) A configuration object for the master process. Contains:
    • timeout: time in milliseconds before a child will be force closed. Default: 10000, 10 seconds.

  Returns a promise that resolves when the server is listening.

• Adios.master.kill(pid) - Method to kill a worker by process id

  • pid - The process id to kill

• Adios.master.term(pid) - Method to terminate a worker by process id, this will call the graceful shutdown defined by the worker.

  • pid - The process id to terminate

  Returns a promise that resolves when the worker is terminated.

• Adios.child.init(cleanCb[, path]) - The initialize function for adios children. Sets up a connection to the master. Note: there can be only one per process and it must be running on a child process.

  • cleanCb - The method to execute when the master is notifying of a shutdown. Must return a promise that resolves when work is done.
  • path - (optional) The socket path to use. Defaults to /var/run/adios.sock

  Returns a promise that resolves when the connection with the master has been established.