XS Advanced - Node.js Module - HDB Connection Error

[rene_mueller02]

Hello everybody,

i try to establish a connection and send some queries to the HANA 2.0 express edition, running on my laptop. I've build a XS Advanced app and now i'm writing a Node.js module using the sap-hdbext and express modules to establish a connection to the HDB like so:

module.exports = function() {
	var app = express();


	passport.use("JWT", new xssec.JWTStrategy(xsenv.getServices({
		uaa: {
			tag: "xsuaa"
		}
	}).uaa));
	app.use(passport.initialize());


	app.use(
		passport.authenticate("JWT", {
			session: false
		}),
		xsHDBConn.middleware()
	);


	//Simple Database Select - In-line Callbacks
	app.route("/simptab")
		.get(function(req, res) {
			var client = req.db;
			client.prepare(
				"select Test from \"project.db.data::SimpleTable\" ",
				function(err, statement) {
					if (err) {
						res.type("text/plain").status(500).send("ERROR: " + error);
						return;
					}
					statement.exec([],
						function(err, results) {
							if (err) {
								res.type("text/plain").status(500).send("ERROR: " + err);
								return;
							} else {
								var result = JSON.stringify({
									Objects: results
								});
								res.type("application/json").status(200).send(result);
							}
						});
				});
		});

I've setup the package.json file and the server.js and everything else just like in the Dev Guide and openSAP course.

But if i go to the URL "https://hxehost:....../node/simptab" to access my node module the following error occurs:

Error: Could not connect to any host: [ undefined:NaN - connect ECONNREFUSED 127.0.0.1 ]   at couldNotOpenConnectionError (/hana/shared/HXE/xs/controller_data/executionagent/executionroot/f6e141e5-a900-460a-a8b9-9052ee21b55d/app/node_modules/hdb/lib/protocol/ConnectionManager.js:130:13)   at ConnectionManager._openConnectionToHost (/hana/shared/HXE/xs/controller_data/executionagent/executionroot/f6e141e5-a900-460a-a8b9-9052ee21b55d/app/node_modules/hdb/lib/protocol/ConnectionManager.js:43:15)   at /hana/shared/HXE/xs/controller_data/executionagent/executionroot/f6e141e5-a900-460a-a8b9-9052ee21b55d/app/node_modules/hdb/lib/protocol/ConnectionManager.js:56:10   at Socket.onerror (/hana/shared/HXE/xs/controller_data/executionagent/executionroot/f6e141e5-a900-460a-a8b9-9052ee21b55d/app/node_modules/hdb/lib/protocol/Connection.js:168:5)   at Socket.g (events.js:291:16)   at emitOne (events.js:96:13)   at Socket.emit (events.js:188:7)   at emitErrorNT (net.js:1276:8)   at _combinedTickCallback (internal/process/next_tick.js:74:11)   at process._tickCallback (internal/process/next_tick.js:98:9)

What could be the cause? I've tried nearly every i could come up with to solve this but nothing worked.

Like i said, i've setup everything just like in the demos.

Please help.

[draschke]

Hi Rene,

we do have exactly the same issue. Could you find out what the reason of this behavior is?

BR,

Dirk

[sasi_reddy7]

Hi All

We are having the same exact problem in Cloud Application Program in Cloud Foundry with Hana 2.0. The app was working fine with CDS oData calls and it stopped working this week with this same exact error. Any help is much appreciated. We already implemented the above suggestions in our Server.js in node service.

Thanks

Sasi