Azure Function Queue Trigger V2 not reading the message

Question

Azure Function Queue Trigger V2 not reading the message

Pedro Junqueira 40

I am trying to read a message from a queue storage.

I am following exactly the tutorial code and running locally using azurite (tested also with a storage).

The the strange thing is that when a new message arrive at the queue the function gets triggered and then moved to poison queue but nothing happens in between.

The logs do not log, therefore I cannot do anything with the message.

@app.queue_trigger(arg_name="azqueue", queue_name="hyper-tyre-to-process",
                               connection="AzureStorageAccount") 
def queue_trigger(azqueue: func.QueueMessage):
   
   logging.info('Python queue trigger function processed a queue item: %s',
                 azqueue.get_body().decode('utf-8'))

User's image

It works but but really does not do the most important thing. Read the message.

What I am doing wrong?

navba-MSFT 27,540 Reputation points Microsoft Employee Moderator

2023-09-26T07:28:44.19+00:00
@Pedro Junqueira Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

I understand that you have a Python QueueTrigger Function app which is not able to read the new message in the queue and you are getting the error Message has reached MaxDequeueCount of 5. Moving message to queue.

You seem to have configured the maxDequeueCount within your host.json file as shown below:

More Info here. You can try to increase this value.

I would start by checking if the Queue has other people processing messages. It might be that this application is just the victim of someone else processing the queue and not completing on the message.

To isolate this, you can try creating a new queue and try adding message to that and check if that works fine.

I used the Azurite storage emulator at my end and wrote the below sample code. It worked fine:

import azure.functions as func import logging def navbademoqueuetrigger(azqueue: func.QueueMessage): logging.info('Python Queue trigger processed a message: %s', azqueue.get_body().decode('utf-8'))

Message added to the Azurite queue:

Output:

Below are the versions used at my end:

Core Tools Version: 4.0.5382 Commit hash: N/A (64-bit)

Function Runtime Version: 4.25.3.21264

Hope this helps.

**

Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

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navba-MSFT 27,540 Reputation points Microsoft Employee Moderator

2023-09-26T07:28:44.19+00:00

@Pedro Junqueira Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

I understand that you have a Python QueueTrigger Function app which is not able to read the new message in the queue and you are getting the error Message has reached MaxDequeueCount of 5. Moving message to queue.

You seem to have configured the maxDequeueCount within your host.json file as shown below:

More Info here. You can try to increase this value.

I would start by checking if the Queue has other people processing messages. It might be that this application is just the victim of someone else processing the queue and not completing on the message.

To isolate this, you can try creating a new queue and try adding message to that and check if that works fine.

I used the Azurite storage emulator at my end and wrote the below sample code. It worked fine:

import azure.functions as func import logging def navbademoqueuetrigger(azqueue: func.QueueMessage): logging.info('Python Queue trigger processed a message: %s', azqueue.get_body().decode('utf-8'))

Message added to the Azurite queue:

Output:

Below are the versions used at my end:

Core Tools Version: 4.0.5382 Commit hash: N/A (64-bit)

Function Runtime Version: 4.25.3.21264

Hope this helps.

**

Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

Answer 1

navba-MSFT 27,540 Microsoft Employee Moderator

@Pedro Junqueira I'm glad to see you were able to resolve your issue.

Thanks for posting your solution so that others experiencing the same thing can easily reference this. Since the Microsoft Q&A community has a policy that the question author cannot accept their own answer, they can only accept answers by others, I'll repost your solution in case you'd like to Accept the answer.

Issue:
You have a Python QueueTrigger Function app which is not able to read the new message in the queue and you are getting the error Message has reached MaxDequeueCount of 5. Moving message to queue.

Resolution:

The above error message is completely misleading and has nothing to do with the encoding issue. The same has been already been reported to MSFT as a bug.

You got the right code from this stackoverflow post.

Here is the code that you have used and it is working when sending the message to be then able to get the message using function trigger.

from azure.storage.queue import (
        QueueClient,
        BinaryBase64EncodePolicy,
        BinaryBase64DecodePolicy
)
queue_client = QueueClient.from_connection_string(
    connection_string,
    queue_name
    )

# Setup Base64 encoding and decoding functions
queue_client.message_encode_policy = BinaryBase64EncodePolicy()
queue_client.message_decode_policy = BinaryBase64DecodePolicy()

for i in range(10):

    print(f'Sending message {i}')
    message = {'id': i, 'message' :'Hello World'}
    message_string = json.dumps(message)
    message_bytes =  message_string.encode('utf-8')
    queue_client.send_message(
        queue_client.message_encode_policy.encode(content=message_bytes)
        )

Pedro Junqueira 40 Reputation points

2023-09-27T01:57:35.87+00:00
Hi @navba-MSFT ,

Thanks a lot for taking the time to look into my problem.

I am using Azure Function V2 and below is my host.json file

There is nothing saying about it queues. It is like this.

{ "version": "2.0", "logging": { "applicationInsights": { "samplingSettings": { "isEnabled": true, "excludedTypes": "Request" } } }, "extensionBundle": { "id": "Microsoft.Azure.Functions.ExtensionBundle", "version": "[3.*, 4.0.0)" } }

That was not the problem.

The issue is that the code in python I used to send the message to the queue was incorrect when it comes to the encoding.

The error message of Message has reached MaxDequeueCount of 5. Moving message to queue.

is completely misleading and has nothing to do with the encoding issue. By the way it has already been reported to MSFT as a bug.

I realized that if I manually add a message to the queue, using the correct encoding, then my original code just work fine.

Then I changed my code to send the message in the right encoding which is Base64 . It is a bit more tricky than just using the base64 python package.

The write code I got was in stack overflow post.

Here is the code that works when sending the message to be then able to get the message using function trigger.

from azure.storage.queue import ( QueueClient, BinaryBase64EncodePolicy, BinaryBase64DecodePolicy ) queue_client = QueueClient.from_connection_string( connection_string, queue_name ) # Setup Base64 encoding and decoding functions queue_client.message_encode_policy = BinaryBase64EncodePolicy() queue_client.message_decode_policy = BinaryBase64DecodePolicy() for i in range(10): print(f'Sending message {i}') message = {'id': i, 'message' :'Hello World'} message_string = json.dumps(message) message_bytes = message_string.encode('utf-8') queue_client.send_message( queue_client.message_encode_policy.encode(content=message_bytes) )
navba-MSFT 27,540 Reputation points Microsoft Employee Moderator

2023-09-27T02:28:04.0133333+00:00

@Pedro Junqueira Thanks for getting back and providing the update. I have also followed up with the assignee of this GitHub bug post. and asked for an update. Thanks again for sharing the working code. This would be beneficial to our community customers.
Pedro Junqueira 40 Reputation points

2023-09-27T08:41:10.62+00:00

@navba-MSFT thanks for this. Cheers
navba-MSFT 27,540 Reputation points Microsoft Employee Moderator

2023-09-29T04:49:45.0466667+00:00

@Pedro Junqueira This is a quick follow-up to check if you had a chance to look at my above comment. Awaiting your reply.
Rafał Gąsiorowski 0 Reputation points

2025-02-02T10:51:28.25+00:00

Thank you for the info on message encoding. I was wondering why my AF triggers reads messages added through portal, but not through Python code and lack of encoding the messages was the reason. Very helpful.

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Azure Function Queue Trigger V2 not reading the message

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