I am currently running a REST API on Amazon EC2 using Node.js (Express).
During a specific REST call, the client receives a reply of approximately 5MB. However, before the client can fully receive the reply, an error message is displayed:
Premature end of Content-Length delimited message body
To investigate this issue further on the server-side, I implemented a connection listener in my Node.js server as shown below:
var app = express();
var server = http.createServer(app);
var port = app.get('port');
server.listen(port);
server.on('error', onError);
server.on('listening', onListening);
server.on('connection', function (socket) {
log.debug('SOCKET OPENED' + JSON.stringify(socket.address()));
socket.setTimeout(300000); //5 minute timeout
socket.on('end', function () {
log.debug('SOCKET END: other end of the socket sends a FIN packet');
});
socket.on('timeout', function () {
log.warn('SOCKET TIMEOUT');
});
socket.on('error', function (error) {
log.warn('SOCKET ERROR: ' + JSON.stringify(error));
});
socket.on('close', function (had_error) {
log.debug('SOCKET CLOSED. IT WAS ERROR: ' + had_error);
});
});
Upon investigation, it was observed that SOCKET TIMEOUT events were being logged in the backend. Even after increasing the socket timeout to 5 minutes, the issue persisted.
Interestingly, when the REST API was hosted on Google Compute Engine previously, this problem did not occur.
What do you think could be causing this issue?
Edit: Below is the code snippet for the REST API call:
In my app.js, I have the following code:
require('./routes/index')(app);
The index.js file inside the routes directory looks like this:
var changeCase = require('change-case');
var express = require('express');
var routes = require('require-dir')();
module.exports = function (app) {
Object.keys(routes).forEach(function (routeName) {
var router = express.Router();
require('./' + routeName)(router);
app.use('/api/' + changeCase.paramCase(routeName), router);
});
};
This script iterates through all the JavaScript files in the routes directory and registers the file names as URL paths in the app.
Below is the code for the specific route where the issue occurs:
module.exports = function (router) {
router.get("/fetch", function (req, res, next) {
itemModel.fetch(req.user.clientId, function (error, items) {
if (error) {
res.status(500).json({error: error});
} else {
res.json(items); //items is a JSON array
}
});
});
}