getaddrinfo ENOTFOUND error - node.js

Question

I had a perfectly running nodejs server on an EC2 instance of Amazon AWS. By mistake, I missed a couple of payments and the service was halted. When I paid and brought the account up to date, I found the server was back in place and was already running.
However, since then, my very first request has started returning the "getaddrinfo ENOTFOUND" error and am not able to check any other request either. This is weird, since the first line in the code to check the health of the server (refer to index.html below) return the desired "All Ok" result. But the subsequent requests gives the ENOTFOUND error. Any help in this will be very much appreciated.
FYI, I have tried stopping and restarting the server, didn't help.
Here is the code of the base file:
require('newrelic');
var express = require('express'),
bodyParser = require('body-parser'),
oauthserver = require('oauth2-server');
var multer = require('multer');
var upload = multer({ dest: '../uploads/' });
var controllernew = require('./controllers/controllernew');
var app = express();
app.use(bodyParser.json({limit: '50mb'}));
app.use(bodyParser.urlencoded({limit: '50mb', extended: true}));
/***************************************************************
********FOLLOWING REQUEST RETURNS ALL OK AS DESIRED*************
****************************************************************/
app.get('/index.html', controllernew.index);
app.oauth = oauthserver({
model: require('./models/modeloauth'),
grants: ['password'],
debug: true,
accessTokenLifetime: 31536000
});
/******************************************************************
*******GETTING ENOTFOUND ERROR FOR THE FOLLOWING REQUEST***********
*******************************************************************/
app.get('/userOTP/:userid/username/:username', controllernew.getUserOTP);
app.all('/oauth/token', app.oauth.grant());
app.all('*', app.oauth.authorise());
app.use(app.oauth.errorHandler());
app.post('/uploadimagenew', upload.single('upload'), function(req, res) {
var controllernew = require('./controllers/controllernew');
controllernew.createImage2(req, res, function(){
console.log(req.file);
console.log(req.body.csvlistevents);
var strArray = req.body.csvlistevents.split("|");
console.log(strArray[3]);
})
});
routes = require("./routes/items")();
app.use(routes);
var server = app.listen(8080, function(){
console.log('server started at ' + server.address().port);
});