I'd like to change a message property before abandoning. The following code don't work. I'm receiving the message with the initial Label.
message.Label = "failed";
message.Abandon();
It it possible to define that message was abandoned?
You cannot update content of an Azure Service Bus Queue message object. Frankly, if I have to update a message content, than there is something wrong in my approach.
You can, however, update the content of an Azure Storage Queue message, using the UpdateMessage method or any of its async friends. In any case, I feel wrong the general approach of touching message content!
For your purpose I suggest that you take a look at DeadLetterQueue feature of Azure SErvice Bus Queues and Topics, or the DequeueCount property of Azure Storage message to determine whether there is something wrong with the message.
Related
Is it possible to implement the following pseudo scenario with an Azure Service Bus?
I have a function that can scale out to 50 instances, it uses a service bus trigger. I would like to guarantee that related messages are only processed if an existing related message is NOT currently being processed.
Let's say I have a message (Message A) being processed by a function instance that's associated with UserID 1234. Another message (Message B) appears on the queue which is also associated with UserID 1234, the service bus should "ignore" it because a related message is already being processed. Another message (Message C) with UserID 9876 appears on the queue, this gets handled straight away because there is no in action message with UserID 9876.
Message A finishes processing and Message B is now picked up.
Currently I have a routing function which consumes the initial service bus trigger and then routes it to one of 10 functions each of which is responsible for messages where the last digit of the UserID is 0-9.
This means that if function "4" is busy with a request it won't be able to process any other requests where the UserID ends with 4, thus guaranteeing the system cannot process a related message at the same time. It does it's job but doesn't scale.
There's no conditional locking. From the description, sounds like you want to process messages associated with the same user ID, one at a time. For that, Azure Service Bus has a feature called Message Sessions.
As far as I know, azure service bus has a locking mechanism built into it. So no matter the message, if you have a single queue you are reading from, when a function picks that message up the rest of your functions would not pick up that same message. To solve the issue of not processing a duplicate message by userID I would recommend using something table storage to validate if that userID has been processed already (So in your function when you pick up a message you insert that into azure table storage before doing any processing and also have a check to see if it exists before processing).
service bus - https://learn.microsoft.com/en-us/azure/service-bus-messaging/message-transfers-locks-settlement
table storage - https://learn.microsoft.com/en-us/azure/cosmos-db/table/quickstart-dotnet?toc=https%3A%2F%2Flearn.microsoft.com%2Fen-us%2Fazure%2Fstorage%2Ftables%2Ftoc.json&bc=https%3A%2F%2Flearn.microsoft.com%2Fen-us%2Fazure%2Fbread%2Ftoc.json&tabs=azure-cli%2Cwindows
In summary I think the solution here would be using multiple technologies and use a central point your scaled out functions could validate against whats processed by other functions, whatever that central database is
I have an Azure Service Bus topic. Messages send to the topic contain application properties.
I want to set permissions on the topic based on values of one or more application properties, i.e. only when identity A sends a message with property e.g. Destination = 'service' the message is allowed to be added to the topic.
The reason behind this: assume a topic where there are multiple publishers and multiple subscribers to consume the messages from the publishers. But each message shall only go to specific consumers using filters. An actor with bad intentions or just by accident could choose a filter value and send the message therefore to wrong consumers. And I don't want to create multiple topics. I want to limit the publishers to send messages to certain consumers by limiting their permissions by message attributes with certain values on a certain topic.
Is this possible? If yes, how?
You can start a separate app which will peek the message in the queue
check for the properties and then abandon the messages.
To peek create a receiver and use receiver.ReceiveMessageAsync();
to peek the message. After this you can apply your logic to filter
the messages using the properties.
After that use AbandonAsync to abandon the message with wrong properties.
// create a reciever and peek the messages.
await using var client = new ServiceBusClient(connectionString);
//reciever
ServiceBusReceiver receiver = client.CreateReceiver(queueName) ;
// get the messages
ServiceBusReceivedMessage receivedMessage = await receiver.ReceiveMessageAsync();
// write you logic for filtering the message
//now we can abandon the message. Here "reason":" Wrong message" is optional
await receivedMessage.AbandonAsync(new Dictionary<string, object> { { "Reason", "wrong properties"} });
Refernce:
Refer the article by sfeldman
Peek messages
You can't use ServiceBus (or any message broker) the way you describe.
My advice is to consider messages only as signals to do something. But the service is entirely responsible to check if the message is legitimate or not (by calling the source service or another source of truth synchronously for example).
Imagine this scenario:
SourceApp send a DeletedEvent{CustomerId="42"}.
DestApp receives this message, and before deleting data related to this customer, makes an HTTP call to the customer service GET CustomerService/42.
If the customer is deleted => perfect
If not... something went wrong, what you described by an actor with bad intentions or just by accident
Also, if you use the same topic for a lot of applications consider using AAD authentication, with managed identity per app. Or at least forbid sharing SAS keys. Every app should have dedicated connection string, scoped to the subscription or the topic with only the access needed.
I need the Notification Message Id that is supposed to be returned from the azure notification hub when sending the message.
I am sending the message from the app backend using the SendGcmNativeNotificationAsync method.
NotificationOutcome outcome = await hub.SendGcmNativeNotificationAsync(notif, tags);
After sending the notification, the outcome.NotificationId property is empty or null. How can I get the Notification Id?
Although the outcome.Result[0].Outcome received has value
"The Notification was successfully sent to the Push Notification System"
but the notifications are not delivered to the registered device.
Also I get a tracking id in outcome.trackingid how can I use it to track the message.
I am using free version of azure portal.
Please suggest
Thanks in advance!
It took me quite some time to figure this out, because it is not clear documented, but the answer is simple: NotificationOutcome.NotificationId is always null when Azure pricing tier is not S1 (Standard).
To figure out the cause of your problem, temporary switch to the S1 pricing tier. Then you will get the NotificationId and Azure will register Per Message Telemetry.
In theory, you should be able to get the results by calling GetNotificationOutcomeDetailsAsync with the NotificationId to get more error info. It can take up to 30 minutes (!) before this call succeeds (if you call it too soon you get a MessagingEntityNotFoundException).
Unfortunately, the result State is mostly Completed, even though the message had a wrong or expired device ID.
The results in the Metrics shown in Azure for your Notification Hub are correct, but I did not find a reliable way yet to retrieve the results on a Per Message base.
Don't forget to switch back to the F1 (Free) pricing tier!
I've looked everywhere for information on this but can't seem to find what i'm looking for.
I've got an azure topic, with one subscription.
The handler for the subscription failed some messages, they've been put on the deadletter queue.
I can access the messages but i'm at a loss for how to restore them.
I don't want to create a copy of the message and send it to the topic. I specifically want to move it to the subscription queue it came from.
Is there any way to do this?
I don't know if this is possible.
What we mostly do to handle & resume messages, is to use the pattern of defering messages. If a handler fails a message, he can then defer the message and keep track of the messagesequence number (typically in a management / tracking database or component).
Whenever the message needs to be reprocessed (retried), a receiver can then specifically get that message (using the same defered message id) and process it again.
Is it possible to send a message directly to a Subscription queue?
Scenario:
A message failed, dropped onto the deadletter, the message has been picked up manually using defer, cloned and needs to be sent to the queue it was first deadlettered on, but NOT the topic.
Can I send a message directly to a subscriber?
I've considered creating a separate retry queue per subscriber, where the handling service will also receive messages from but i'd rather not do this.
this is a similar question to the one you asked earlier: Azure Service Bus Subscriber Deadletter
this is not possible, as far as I know. the only thing you could do is to add an extra filter on every subscription that has something like SubscriptionName='SubscriptionA'. If you then want to send you deadlettered message to the specific subscription, you can add a property SubscriptionName to it, to achieve your goal. Take into account that you also have to make sure that in your original filter, you add a condition to indicate that the property SubscriptionName should not exist.
I agree however, that it would be a nice scenario to 'undeadletter' a message, so that it ends up again in his original subscription.