NodeJS- Routing / Redis

This is an example for multiple listening ports.

 var http = require('http');  
 var connect = require('connect');  
 http.createServer(function(request, response) {  
      response.writeHead(200, {'Content-Type': 'text/plain'});  
      response.end('Hello World from 8124\n');  
 }).listen(8124);  
 var server = connect.createServer(function(req, res) {  
  res.writeHead(200, { 'Content-Type': 'text/plain' });  
  res.end('Hello World from 3000');  
 }).listen(3000);  
 console.log('Server running at http://127.0.0.1:8124 & 3000');  

2. Redis Example

 var redis = require('redis'),  
      redis_client = redis.createClient();   
 redis_client.on('error', function(err) {  
      console.log("Error: " + err);  
 });   
 redis_client.set("Hello", "World", redis.print);  
 redis_client.hset("Hash", "field1", "value1", redis.print);  
 redis_client.hset(["Hash", "field2", "value2"], redis.print);  
 redis_client.hkeys("Hash", function(err, replies) {  
      console.log(replies.length + " replies:");  
      replies.forEach(function(reply, i) {  
           console.log("  " + i + ": " + reply);  
      });  
      // redis_client.quit();   
 });   
 var instruction = {  
      "id": "test1",  
      "musl": [ "1.mus", "2.mus", "3.mus"],  
      "hosts": {  
           "host_0": "a1",  
           "host_1": "a2"  
      }  
 };   

/// --> this is not supported. (no nested object.)  
 redis_client.hmset("Inst1", instruction); 


 redis_client.hgetall("Inst1", function(err, obj) {  
      console.dir(obj);   
 });   
 var str_instruction = JSON.stringify(instruction);  
 console.log("str: " + str_instruction);   
 redis_client.set("instruction", str_instruction);   
 redis_client.get("instruction", function(err, value) {  
      console.log("get: " + value);   
      console.dir(JSON.parse(value));   
 });   
 // Publish/Subscribe  
 redis_client.on('message', function(channel, message) {  
      console.log("client1 channel " + channel + ": " + message);  
 });  
 redis_client.subscribe('testengine');   

3. Redis PubSub Example

 var redis = require("redis"),  
   client1 = redis.createClient(), client2 = redis.createClient(),  
   msg_count = 0;  
 client1.on("subscribe", function (channel, count) {  
   client2.publish("a nice channel", "I am sending a message.");  
   client2.publish("a nice channel", "I am sending a second message.");  
   client2.publish("a nice channel", "I am sending my last message.");  
 });  
 client1.on("message", function (channel, message) {  
   console.log("client1 channel " + channel + ": " + message);  
   msg_count += 1;  
   if (msg_count === 3) {  
     client1.unsubscribe();  
     client1.end();  
     client2.end();  
   }  
 });  
 client1.incr("did a thing");  
 client1.subscribe("a nice channel");