title: events.js:72 throw er; // Unhandled 'error' event
body: <p>I am trying to do on authetication and authorization, from some of the post i found out to install npm, I've install npm too still am unable to solve the error:</p>
  <pre><code>$ node blog.js
  Blog API is starting on port 6379
   events.js:72
          throw er; // Unhandled 'error' event
                ^
  
   Error: listen EADDRINUSE
               at errnoException (net.js:904:11)
               at Server._listen2 (net.js:1042:14)
               at listen (net.js:1064:10)
               at Server.listen (net.js:1138:5)
               at Function.app.listen  (./node_modules/express/lib/application.js:531:24)
               at Object.&lt;anonymous&gt; (./api/blog.js:9:5)
               at Module._compile (module.js:456:26)
               at Object.Module._extensions..js (module.js:474:10)
               at Module.load (module.js:356:32)
               at Function.Module._load (module.js:312:12)
  </code></pre>