a proper fibonacci server in node. it will light up all your cores.

fib.js

var http = require('http')
var fork = require('child_process').fork;

function fib(n) {
  if (n < 2) {
    return 1;
  } else {
    return fib(n - 2) + fib(n - 1);
  }
}

if (process.argv[2] == 'fib') {
  var r = fib(40);
  process.send({ result: r });
  process.exit(0);
} else {
  var server = http.createServer(function(req, res) {
    var child = fork(__filename, [ 'fib' ]);
    child.on('message', function(m) {
      res.writeHead(200);
      res.end(m.result + "\n");
    });
  });
  server.listen(8000);
  console.log("server online at http://localhost:8000/")
}

@ry : the threads_a_gogo version: https://gist.github.com/2031338 is only nineteen lines :

var http = require('http')
var pool = require('threads_a_gogo').createPool(5).all.eval(fib);

function fib (n) {
  if (n < 2) {
    return 1;
  } else {
    return fib(n - 2) + fib(n - 1);
  }
}

var server = http.createServer(function(req, res) {
  pool.any.eval('fib(40)', function (err, data) {
    res.writeHead(200);
    res.end(data + "\n");
  });
});
server.listen(8000);
console.log("server online at http://localhost:8000/")

@ry : And the threads_a_gogo version is almost twice as fast

$ time curl localhost:8000 //the threads_a_gogo version
165580141

real    0m2.550s
user    0m0.004s
sys 0m0.005s

$ time curl localhost:8000 // @ryah version
165580141

real    0m4.723s
user    0m0.004s
sys 0m0.004s

And uses less than 1/4th the memory:

ab -c 10 -n 10 http://127.0.0.1:8000 ->

@ry : 11 node processes, 22 threads
11.0+10.9+11.0+11.1+11.1+11.1+11.0+11.0+11.1+10.8+10.2= 120.3 MB
26.3 seconds
0.38 requests/s

threads_a_gogo: 1 node process, 12 threads
29.5 MB
13.2s
0.75 requests/s

@ry @xk

And here's a version using threads_a_gogo that uses 14 lines and accepts input: https://gist.github.com/2023979

Pass input via curl localhost:8000/# (i.e. curl localhost:8000/42)

OMG and heres a version with just one line of code

var http=require("http"),pool=require("threads_a_gogo").createPool(5).all.eval(fib);function fib(a){return 2>a?1:fib(a-2)+fib(a-1)}var server=http.createServer(function(a,b){pool.any.eval("fib(40)",function(a,c){b.writeHead(200);b.end(c+"\n")})});server.listen(8E3);console.log("server online at http://localhost:8000/");

Point being.. Lines of code are pointless.

oh god, node fanboys make me wanna puke :[

@kybernetyk your profile just made me puke