Testing performance of node async functions with internal domains see: http://www.lighthouselogic.com/using-a-new-domain-for-each-async-function-in-node/

nodeinternaldomain

var Benchmark = require('benchmark');
var fs = require("fs");
var domain = require("domain");

var d = domain.create().on('error', function(err){ console.log("Caught" + err); process.exit();})

var j_ = 10000000; 


function intensive(){
                 
	var s = 0;                
	for (var i = 0; i < j_; i++) s = i;                
	for (var i = 0; i < j_; i++) s = i;                
	for (var i = 0; i < j_; i++) s = i;                
	for (var i = 0; i < j_; i++) s = i;

}

function readJsonWithoutTryCatchIntensive(filename, callback) { 
     fs.readFile(filename, function (err, content) {     
          if (err) { 
               return callback(err); 
          } 
         
          var data = JSON.parse(content.toString()); 
          intensive();
               
          return callback(null, data); 
     }); 
}

function readJsonWithInternalDomainIntensive(filename, callback) { 
     var d = domain.create().on('error', function(err){ return callback(err)})
     fs.readFile(filename, d.intercept(function (content) {     
          var data = JSON.parse(content.toString()); 
          intensive();
               
          return callback(null, data); 
     })); 
}

function readJsonWithInternalDomain(filename, callback) { 
	var d = domain.create().on('error', function(err){ return callback(err)})
    fs.readFile(filename, d.intercept(function (content) {     

		var data = JSON.parse(content.toString()); 
		
		var s = 0;                
		for (var i = 0; i < j_; i++) s = i;                
		for (var i = 0; i < j_; i++) s = i;                
		for (var i = 0; i < j_; i++) s = i;                
		for (var i = 0; i < j_; i++) s = i;

		return callback(null, data); 
    })); 
}

function readJsonWithTryCatch(filename, callback) { 
     fs.readFile(filename, function (err, content) {     
          if (err) { 
               return callback(err); 
          } 
         
          var data = JSON.parse(content.toString()); 
    	try {                    
			var s = 0;                
			for (var i = 0; i < j_; i++) s = i;                
			for (var i = 0; i < j_; i++) s = i;                
			for (var i = 0; i < j_; i++) s = i;                
			for (var i = 0; i < j_; i++) s = i;

	      } catch (e) { 
               return callback(e); 
          }          
          return callback(null, data); 
     }); 
}


var suite = new Benchmark.Suite;

// add tests
suite.add('Control (readJSONWithoutTryCatchIntensive) ', function(deferred) {
  readJsonWithoutTryCatchIntensive("./test.json", function(){
  		deferred.resolve();
  });
}, {'defer': true}).add('readJsonWithInternalDomainIntensive', function(deferred) {
  	readJsonWithInternalDomainIntensive("./test.json", function(){
  		deferred.resolve();
  });
}, {'defer': true}).add('readJSONWithInternalDomain', function(deferred) {
  	readJsonWithInternalDomain("./test.json", function(){
  		deferred.resolve();
  });
}, {'defer': true}).add('readJsonWithTryCatch', function(deferred) {
  	readJsonWithTryCatch("./test.json", function(){
  		deferred.resolve();
  });
}, {'defer': true}).on('cycle', function(event) {
  console.log(String(event.target));
}).on('complete', function() {
  console.log('Fastest is ' + this.filter('fastest').pluck('name'));
}).run({ 'async': true });
// Slow!