Timeout value of 00:05:00 was exceeded by function: Functions.MyFunc.

I’m trying to setup a function app using script, steps are listed below.

Repro steps

Provide the steps required to reproduce the problem

1. Create dynamic function app using json template

2. Setting environment variable (some connection string) through Azure CLI 2.0

3. Create a folder as a function name under site/wwwroot/ (Kudu REST API)

4. Upload files into the created folder (through FTP)

5. run “npm install” (Kudu REST API)

My function code:

'use strict';

const Client = require('azure-iothub').Client;
const Message = require('azure-iot-common').Message;
const iotHubConnectionString = process.env['speech-recognition-iothub'];

module.exports = function (context, myEventHubMessage) {
    context.log(myEventHubMessage);
    if (myEventHubMessage.DeviceID) {
        const cloudClient = Client.fromConnectionString(iotHubConnectionString);
        cloudClient.open(function (err) {
            if (err) {
                console.log('Could not connect: ' + err.message);
            } else {
                console.log('Client connected');
                const message = new Message(`Pong - ${new Date().toTimeString()}`);
                cloudClient.send(myEventHubMessage.DeviceID, message, function (err, res) {
                    if (err) {
                        context.log(`Error in send C2D message: ${err}`);
                    } else {
                        context.log(`send status: ${res.constructor.name}`);
                    }
                });
            }
            context.done();
        });
    }
};

Actual behavior

Then I send some msg to my IoT Hub. The function app is keeping logging “function app start”

logs can be seen here,

Actually, if I do nothing, the function app still keeps logging “function app start”

[tohling]

@jdneo, could you try changing your Function to process the EventHub messages in batches? You can do so with the following 2 steps:

1. Add “cardinality”: “many” as a new property in your input binding in your function.json file.
2. Encapsulate your Function code in a FOR-loop to process an array of events instead. I changed the name of your input-binding to myEventHubMessages to indicate plurality.

'use strict';

const Client = require('azure-iothub').Client;
const Message = require('azure-iot-common').Message;
const iotHubConnectionString = process.env['speech-recognition-iothub'];

// renamed your input-binding to myEventHubMessages
module.exports = function (context, myEventHubMessages) {
  context.log(util.format("Node.js script processed %d events", myEventHubMessages.length));
  context.log("IsArray", util.isArray(myEventHubMessages));
  const cloudClient = Client.fromConnectionString(iotHubConnectionString);

  cloudClient.open(function (err) {
  if (err) {
    context.log('Could not connect: ' + err.message);
  } else {
    context.log('Client connected');
    for (i = 0; i < myEventHubMessages.length; i++)  
	{
      context.log(myEventHubMessages[i]);
      if (myEventHubMessages[i].DeviceID) {
        const message = new Message(`Pong - ${new Date().toTimeString()}`);
		cloudClient.send(myEventHubMessages[i].DeviceID, message, function (err, res) {
		  if (err) {
		    context.log(`Error in send C2D message: ${err}`);
		  } else {
		    context.log(`send status: ${res.constructor.name}`);
		  }
		});	
	  }
	}	
  }
	
  cloudClient.close()// not sure if this is the syntax in Node for cloudClient
  context.done();
};

A similar Function setup can be found at: https://github.com/Azure/azure-webjobs-sdk-script/tree/dev/sample/EventHubTrigger

[jdneo]

Thank you guys! According to your suggestion, I figure out the mistakes I made:

1. context.done() should be ensured to be called

e.g.

cloudClient.open(function (err) {
    if (err) {
        // error handler
        context.done()
    } else {
        //success handler
        context.done()
    }
});

Put the context.done() inside the callback function can make the ‘function complete’ log always show in the last step of the function execution

1. cloudClient.close() should be called. In my investigation, if cloudClient.close() is not called, it will encounter some problems to open the client in the next function trigger.

Thank you again!