forkfriend

dead simple worker process manager. respawn children. load balance work amongst children.

example

var forkfriend = require('friend');
var friend = forkfriend();

// make 3 somefriend.js worker with arguments
friend.add('somefriend.js',['-a',1],3);

// workers for the same file get the same args as the first. 
// multiple calls to add add that many more to the pool
friend.add('somefriend.js')

friend.send('hey one of you work on this');

friend.on('message',function(message,workername,worker){
  // message is the data the child sent.
  // workername === 'somefriend.js'
  // worker instanceof ChildProcess
})

// when you are all done
friend.stop();

api

forkfriend forkfriend(options)

• options {} [optional]
  • respawnInterval
    • defaults to 500 ms. this is the max speed that new children will be spawned to prevent pegging the cpu on broken workers
  • maxQueue
    • defaults to 100. this is the maximum number of pending messages for workers that should be held while waiting for a functional worker to spawn. after this messages will be dropped but a drop event will be emitted so you application can choose how to handle the issue.
• returns "friend" an EventEmitter

friend

• add(script,arguments [optional],num [optional])
• add(script,num [optional])
  • script is the path to the javascript file you want to fork
  • arguments are passed to fork as argv of your child process
  • the number of children you want to add to the pool. this is the same as calling add multiple times.
• remove(script)
• remove(script, num [optional])
• remove(script,cp ChildProcess [optional])
  • remove a worker from the pool for script
  • if cp is provided this specifc child is removed
  • if num is provided
• get(script)
  • get an array of the child processes in the pool for script
• send (message, script [optional])
  • the message to send to one worker of each pool
  • send the message to a worker spawned from "script"
• stop ()
  • stops the show. kills all child processes so your script can exit cleanly.
• refork (script, cp ChildProcess [optional])
  • kill and start a specific worker or any in the pool

friend events

• message (message,script,args,cp ChildProcess)
  • a worker has sent you a message
• worker (script,args,cp ChildProcess)
  • a new worker has been forked for this script
• worker-exit (code,script,args,cp ChildProcess)
  • a worker has exited. the friend will try to refork it
• worker-disconnect (script,args,cp ChildProcess)
  • a child has closed its communication channel with this process. the friend will try to kill it.
• worker-error (error,script,args,cp ChildProcess)
  • a worker has had an error event, the friend will try to refork it.
• drop
  • too many messages could not be sent to the workers for this script.

what does a worker look like

process.on('message',function(data){
  // do somthing
  // tell friend about it
  process.send('hey i worked onn '+data);
});

woo hooo.

let me know if this is helpful or if you have any issues.