Error from Azure IoT Hub library when sending a message - node.js

Question

Im using the Node.JS libraries for Azure IoT Hub to send some telemetry data, and intermittently I get the following error thrown from the libraries.
Unhandled rejection TypeError: Cannot read property 'on' of undefined
at C:\Source\Messenger\app.js:156:17
at Amqp. (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\lib\amqp.js:157:17)
at C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\lib\amqp.js:54:19
at C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\lib\amqp.js:84:17
at tryCatcher (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\util.js:11:23)
at Promise._settlePromiseFromHandler (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\promise.js:489:31)
at Promise._settlePromise (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\promise.js:546:18)
at Promise._settlePromise0 (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\promise.js:591:10)
at Promise._settlePromises (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\promise.js:670:18)
at Async._drainQueue (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\async.js:129:16)
at Async._drainQueues (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\async.js:139:10)
at Immediate.Async.drainQueues [as _onImmediate] (C:\Source\Messenger\node_modules\azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10\node_modules\bluebird\js\release\async.js:16:14)
At the moment im running my scripts through forever so it recovers when the error is generated.
Has anyone else had this issue and managed to resolve it ?
My code looks like as follows
azureClient = azureDevice.Client.fromConnectionString(connectionString, azureDevice.Amqp);
var message = new azureDevice.Message(JSON.stringify('TEST MESSAGE'));
azureClient.sendEvent(message, function (err) {
if (err != null) {
Configure();
}
});

Answer 1

For this issue, I recommend you can use the AMQPWS or HTTP transport to send and receive messages.
Please refer to my steps to achieve to send and receive the message:
Firstly, we should create a device and get the device id and SAS. After created the IOT hub on Azure new portal, I ran those command on node.js command line:
create IOT hub on new portal.
npm install -g iothub-explorer
iothub-explorer HostName=****.azure-devices.net;SharedAccessKeyName=iothubowner;SharedAccessKey=****/****= create mydevice --connection-string
I got the result as following:
Created device mydevice
-
deviceId: mydevice
generationId: 635881160181557968
etag: MA==
connectionState: Disconnected
status: enabled
statusReason: null
connectionStateUpdatedTime: 0001-01-01T00:00:00
statusUpdatedTime: 0001-01-01T00:00:00
lastActivityTime: 0001-01-01T00:00:00
cloudToDeviceMessageCount: 0
authentication:
SymmetricKey:
primaryKey: ****/****=
secondaryKey: ****/****=
-
connectionString: HostName=****.azure-devices.net;DeviceId=mydevice;SharedAccessKey=****/****=
Secondly, I installed the SDK on node.js project, the folder structure is same as this picture:
Thirdly, I run this code on my project:
var device = require('azure-iot-device');
var connectionString = 'HostName=****.azure-devices.net;DeviceId=mydevice;SharedAccessKey=****/****=';
var client = device.Client.fromConnectionString(connectionString,device.AmqpWS);
setInterval(function () {
var windSpeed = 10 + (Math.random() * 4); // range: [10, 14]
var data = JSON.stringify({ deviceId: 'mydevice', windSpeed: windSpeed });
var message = new device.Message(data);
message.properties.add('myproperty', 'myvalue');
console.log("Sending message: " + message.getData());
client.sendEvent(message, printResultFor('send'));
}, 1000);
client.getReceiver(function (err, receiver) {
receiver.on('message', function (msg) {
console.log('Id: ' + msg.properties.messageId + ' Body: ' + msg.body);
receiver.complete(msg, function () {
console.log('completed');
// receiver.reject(msg, function() {
// console.log('rejected');
// });
// receiver.abandon(msg, function() {
// console.log('abandoned');
// });
});
receiver.on('errorReceived', function (err) {
console.warn(err);
});
});
});
function printResultFor(op) {
return function printResult(err, res) {
if (err) console.log(op + ' error: ' + err.toString());
if (res) console.log(op + ' status: ' + res);
};
}
it works fine. Also if you used the "Http" transport, it also works fine.
You need use this code:
var client = device.Client.fromConnectionString(connectionString);
This is the reason why I recommend you use the AMQPWS, because of this code in "azure-iot-device\node_modules\azure-iot-common\node_modules\amqp10-transport-ws":
if (this.uri.startsWith('wss')) {
var wsTransport = require('amqp10-transport-ws');
wsTransport.register(amqp10.TransportProvider);
}
If the URI is format with 'wss', it will be register the AMQP transport. But AMQP transport's format is like "amqp://". Hope this helps.

Answer 2

The Azure IoT Hub was by far a preview feature service on Azure. And the Azure IoT device SDK for Node.js is on the fast development.
I am trying to involve someone familiar with this topic to further look at this issue. There might be some time delay.
Appreciate your patience.