I have created a azure function with event hub trigger and keep getting this error "The listener for function 'Transfers.OrdersFunction was unable to start. System.Private.CoreLib: One or more errors occurred. (A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)." when I run debugger. I've followed this code: https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-event-hubs-trigger?tabs=in-process%2Cfunctionsv2%2Cextensionv5&pivots=programming-language-csharp and I am using Visual Studio 2022
Usually, this problem is related to your dev machine firewall blocking ports 5671 and 5672. Check this out:
https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-amqp-protocol-guide
If you can’t open those tpc ports, there is a trick for that. Add this to the end of your connection string: TransportType=AmqpWebSockets
But could be how you added the connection string to the code. You must make sure you get the connection string for a specific event hub in a namespace:
https://learn.microsoft.com/en-us/azure/event-hubs/event-hubs-get-connection-string#connection-string-for-a-specific-event-hub-in-a-namespace
When you apply that to the code, make sure you remove the "EntityPath=" part.
For example , consider the connections string is :
"Endpoint=sb://myhub.servicebus.windows.net/;SharedAccessKeyName=mypolicy;SharedAccessKey=bc34534534543l+4wyWi5jbrQ=;EntityPath=myhub;"
remove the entity path and add it to the "local.settings.json" as you connection string setting
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "UseDevelopmentStorage=true",
"FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
"MyConnSetting": "Endpoint=sb://myhub.servicebus.windows.net/;SharedAccessKeyName=mypolicy;SharedAccessKey=bc34534534543l+4wyWi5jbrQ=;TransportType=AmqpWebSockets"
}
}
than add the connection string setting and entity path value like this:
[Function("Function1")]
public void Run([EventHubTrigger("myhub", Connection = "MyConnSetting")] string[] input)
{
_logger.LogInformation($"First Event Hubs triggered message: {input[0]}");
}
Remember this is just a way to force the trigger to use websockets. once you deploy you can set it to use AMQP.
Hope this help!
Related
I am working on multiple Firebase cloud functions (all hosted in the same region) that connect with a GCP hosted Redis instance in the same region, using a VPC connector. I am using version 3.0.2 of the nodejs library for Redis. In the cloud functions' debug logs, I am seeing frequent connection reset logs, triggered for each cloud function with no fixed pattern around the timeline for the connection reset. And each time, the error captured in the error event handler is ECONNRESET. While creating the Redis instance, I have provided a retry_strategy to reconnect after 5 ms with maximum of 10 such attempts, along with the retry_unfulfilled_commands set to true, expecting that any unfulfilled command at the time of connection reset will be automatically retried (refer the code below).
const redisLib = require('redis');
const client = redisLib.createClient(REDIS_PORT, REDIS_HOST, {
enable_offline_queue: true,
retry_unfulfilled_commands: true,
retry_strategy: function(options) {
if (options.error && options.error.code === "ECONNREFUSED") {
// End reconnecting on a specific error and flush all commands with
// a individual error
return new Error("The server refused the connection");
}
if (options.attempt > REDIS_CONNECTION_RETRY_ATTEMPTS) {
// End reconnecting with built in error
console.log('Connection retry count exceeded 10');
return undefined;
}
// reconnect after 5 ms
console.log('Retrying connection after 5 ms');
return 5;
},
});
client.on('connect', () => {
console.log('Redis instance connected');
});
client.on('error', (err) => {
console.error(`Error connecting to Redis instance - ${err}`);
});
exports.getUserDataForId = (userId) => {
console.log('getUserDataForId invoked');
return new Promise((resolve, reject) => {
if(!client.connected) {
console.log('Redis instance not yet connected');
}
client.get(userId, (err, reply) => {
if(err) {
console.error(JSON.stringify(err));
reject(err);
} else {
resolve(reply);
}
});
});
}
// more such exports for different operations
Following are the questions / issues I am facing.
Why is the connection getting reset intermittently?
I have seen logs that even if the cloud function is being executed, the connection to Redis server lost resulting in failure of the command.
With retry_unfulfilled_commands set to true, I hoped it will handle the scenario as mentioned in point number 2 above, but as per debug logs, the cloud function times out in such scenario. This is what I observed in the logs in that case.
getUserDataForId invoked
Retrying connection after 5 ms
Redis instance connected
Function execution took 60002 ms, finished with status: 'timeout' --> coming from wrapper cloud function
Should I, instead of having a Redis connection instance at global level, try to have a connection created during each such Redis operation? It might have some performance issues as well as issues around number of concurrent Redis connections (since I have multiple cloud functions and all those will be creating Redis connections for each simultaneous invocation), right?
So, how to best handle it since I am facing all these issues during development itself, so not really sure if it's code related issue or some infrastructure configuration related issue.
This behavior could be caused by background activities.
"Background activity is anything that happens after your function has
terminated"
When the background activity interferes with subsequent invocations in Cloud Functions, unexpected behavior and errors that are hard to diagnose may occur. Accessing the network after a function terminates usually leads to "ECONNRESET" errors.
To troubleshoot this, make sure that there is no background activity by searching the logs for entries after the line saying that the invocation finished. Background activity can sometimes be buried deeper in the code, especially when asynchronous operations such as callbacks or timers are present. Review your code to make sure all asynchronous operations finish before you terminate the function.
Source
I've been trying to use the javacscript version of the Eclipse Paho MQTT client to access the Google IOTCore MQTT Bridge, as suggested here:
https://cloud.google.com/iot/docs/how-tos/mqtt-bridge
However, whatever I do, any attempt to connect with known good credentials (working with other clients) results in this connection error:
errorCode: 7, errorMessage: "AMQJS0007E Socket error:undefined."
Not much to go on there, so I'm wondering if anyone has ever been successful connecting to the MQTT Bridge via Javascript with Eclipse Paho, the client implementation suggested by Google in their documentation.
I've gone through their troubleshooting steps, and things seem to be on the up and up, so no help there either.
https://cloud.google.com/iot/docs/troubleshooting
I have noticed that in their docs they have sample code for Java/Python, etc, but not Javascript, so I'm wondering if it's simply not supported and their documentation just fails to mention as such.
I've simplified my code to just use the 'Hello World' example in the Paho documentation, and as far as I can tell I've done things correctly (including using my device path as the ClientID, the JWT token as the password, specifying an 'unused' userName field and explicitly requiring MQTT v3.1.1).
In the meantime I'm falling back to polling via their HTTP bridge, but that has obvious latency and network traffic shortcomings.
// Create a client instance
client = new Paho.MQTT.Client("mqtt.googleapis.com", Number(8883), "projects/[my-project-id]/locations/us-central1/registries/[my registry name]/devices/[my device id]");
// set callback handlers
client.onConnectionLost = onConnectionLost;
client.onMessageArrived = onMessageArrived;
// connect the client
client.connect({
mqttVersion: 4, // maps to MQTT V3.1.1, required by IOTCore
onSuccess:onConnect,
onFailure: onFailure,
userName: 'unused', // suggested by Google for this field
password: '[My Confirmed Working JWT Token]' // working JWT token
function onFailure(resp) {
console.log(resp);
}
// called when the client connects
function onConnect() {
// Once a connection has been made, make a subscription and send a message.
console.log("onConnect");
client.subscribe("World");
message = new Paho.MQTT.Message("Hello");
message.destinationName = "World";
client.send(message);
}
// called when the client loses its connection
function onConnectionLost(responseObject) {
if (responseObject.errorCode !== 0) {
console.log("onConnectionLost:"+responseObject.errorMessage);
}
}
// called when a message arrives
function onMessageArrived(message) {
console.log("onMessageArrived:"+message.payloadString);
}
I'm a Googler (but I don't work in Cloud IoT).
Your code looks good to me and it should work. I will try it for myself this evening or tomorrow and report back to you.
I've spent the past day working on a Golang version of the samples published on Google's documentation. Like you, I was disappointed to not see all Google's regular languages covered by samples.
Are you running the code from a browser or is it running on Node.JS?
Do you have a package.json (if Node) that you would share too please?
Update
Here's a Node.JS (JavaScript but non-browser) that connects to Cloud IoT, subscribes to /devices/${DEVICE}/config and publishes to /devices/${DEVICE}/events.
https://gist.github.com/DazWilkin/65ad8890d5f58eae9612632d594af2de
Place all the files in the same directory
Replace values in index.js of the location of Google's CA and your key
Replaces [[YOUR-X]] values in config.json
Use "npm install" to pull the packages
Use node index.js
You should be able to pull messages from the Pub/Sub subscription and you should be able to send config messages to the device.
Short answer is no. Google Cloud IoT Core doesn't support WebSockets.
All the JavaScript MQTT libraries use WebSocket because JavaScript is restricted to perform HTTP requests and WebSocket connections only.
I have a grails project which uses Spring websockets. I have implemented the DefaultHandshakeHandler to create random principal name for each new session and use convertAndSendToUser to send messages.
Everything works fine in local run. I am also able to deploy the WAR file on an AWS EC2 Linux Instance running latest tomcat. The file deploys fine and the Connect and Disconnect events on websockets can be detected correctly.*
The only problem is, My CustomHandshakeHandler's determineUser does not get called on production. Due to this my StompHeaderAccessor's principal is always null and the code starts spitting NPEs.
This is how i have declared the CustomHandshakeHandler :
class CustomHandshakeHandler extends DefaultHandshakeHandler {
#Override
protected Principal determineUser(ServerHttpRequest request,
WebSocketHandler wsHandler,
Map<String, Object> attributes) {
// Generate principal with UUID as name
return new StompPrincipal(UUID.randomUUID().toString())
}
}
This is how i set the handshake handler configuration :
#Override
void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) {
stompEndpointRegistry.addEndpoint("/ws-ep") // Set websocket endpoint to connect to
.setHandshakeHandler(new CustomHandshakeHandler()) // Set custom handshake handler
.withSockJS() // Add Sock JS support for frontend
}
I tried deploying the same WAR file on local Tomcat 8 and it again works fine. It seems problem happens due to AWS. I also searched for some other AWS and websocket related issues. I came across some ELB compatibility related things but i Don't think that's my case since my websockets are working fine (Events are being received)
Can someone please help out or point me in right directions
Problem was with Nginx settings which upgrade the Http Request to WS request. This question helped a lot : Spring WebSocket: Handshake failed due to invalid Upgrade header: null
I am quite new to django-websocket-redis and as normal I am facing some problems.
I have established a communication from the client to the server and vice versa using Websockets for Redis.
I would like to detect when a client is reconnected or disconnected from the server (meaning when the connection is closed and/or opened again), so that I implement a mechanism where clients are responsible for asking "what did I miss" when they reconnect, and then query the data that they missed.
Currently my client code is like this (fiddle here).
I can detect when the connections is established for the first time, but not when websocket connection is broken and reconnected.
Any ideas on how can i do that ?
The problem is with the function name which you have set it should not be on_connecting() instead it should be only the name of the function on_connecting.
Below is the code, replace your code with below one and check if that works.
var ws4redis = WS4Redis({
uri: '{{ WEBSOCKET_URI }}foobar?subscribe-broadcast&publish-broadcast&echo',
receive_message: receiveMessage,
connecting: on_connecting,
connected: on_connected,
error: on_error,
disconnected: on_disconnected,
close: on_close,
open: on_open,
});
When you write on_connecting() the functions are getting called when the WS4redis is been initialized that's why you see the console log for all the events
Our new phone system is making use of Asterisk manager API which allows to read events and issue commands over a TCP/IP stream. My question is.. Is there any way at all to use ColdFusion to read (and in-turn process) the stream of events? As of now I'm able to view the phone events (incoming calls, transfers, hang-ups etc) via telnet and I'm wondering if it's possible to use a ColdFusion event gateway to process these events as they come over?
Once the initial connection is made (via telnet), I have to submit the following key:values in order to authenticate the connection before the stream begins.
Action: login<CRLF>
Username: usr<CRLF>
Secret: abc123<CRLF>
<CRLF>
Just wanted to specify that as I'm not sure if that's a deal-breaker with possibly using a web service in this manner. Also note we are using ColdFusion 10 Enterprise.
I realize this is an old thread, but I am posting this in case it helps the next guy ....
AFAIK, it cannot be done with a standard CF Event Gateway. However, one possibility is using Asterisk-Java. It is a java library that allows communication with an Asterisk Server. More specifically it Manager interface:
... is capable of sending [actions] and receiving [responses] and
[events]. It does not add any further functionality but rather
provides a Java view to Asterisk's Manager API (freeing you from
TCP/IP connection and parsing stuff).
So it can be used to issue commands to the server, and receive events, just like telnet.
Starter example:
Download the Asterisk-Java jar and load it via this.javaSettings in your Application.cfc
Create a ManagerConnection with the settings for your Asterisk server
factory = createObject("java", "org.asteriskjava.manager.ManagerConnectionFactory");
connection = factory.init( "hostNameOrIP"
, portNum
, "userName"
, "theSecret" ).createManagerConnection();
Create a CFC to act as a listener. It will receive and handle events from Asterisk:
component {
public void function onManagerEvent(any managerEvent)
{
// For demo purposes, just output a summary of the event
WriteLog( text=arguments.managerEvent.toString(), file="AsteriskLog" );
}
}
Using a bit of dynamic proxy magic, register the CFC with the connection:
proxyListener = createDynamicProxy("path.YourCFCListener"
, ["org.asteriskjava.manager.ManagerEventListener"]);
connection.addEventListener( proxyListener );
Login to the server to begin receiving events. Setting the appropriate event level: "off", "on" or csv list of available events - "system", "call" and/or "log".
connection.login("on");
Run a simple "Ping" test to verify everything is working. Then sleep for a few seconds to allow some events to flow. Then close the connection.
action = createObject("java", "org.asteriskjava.manager.action.PingAction").init();
response = application.connection.sendAction(action);
writeDump(response.getResponse());
// disconnect and stop events
sleep(4000);
connection.logoff();
Check the demo log file. It should contain one or more events.
"Information","http-bio-8500-exec-4","10/14/16","15:17:19","XXXXX","org.asteriskjava.manager.event.ConnectEvent[dateReceived=Fri Oct 14 15:17:19 CDT 2016,....]"
NB: In a real application, the connection would probably be opened once, in OnApplicationStart, and stored in a persistent scope.
Events would continue to stream as long as the connection remained open. The connection should only be closed when the application
ends, to halt event streaming.
Yes-- you'd want to use a Socket Gateway. Ben Nadel has a great writeup about how to do this: Using Socket Gateways To Communicate Between ColdFusion And Node.js
Although he uses Node.js in his example, you should be able to use his guide to set up the Socket Gateway, then handle the data passed to it as you see fit.
What you want is a server-side TCP client. I suggest easySocket, a simple UDF that allows you to send TCP messages via Coldfusion by utilizing Java sockets.