How to purge messages for Service Bus Topic Subscription

Question

Just wondering the best way (even if via Portal, Powershell, or C#) to purge the messages off of a Service Bus Topic's Subscription.

Imagine we have a topic with 4 subscriptions, and we only want to purge the messages from one of the subscriptions.

I have a feeling the only way may be to read the messages in a while loop, but hoping for something better.

UPDATE:

Apart from using code, you can use the Server Explorer as suggested in the answer - right click subscription and purge messages:

Using SBExplorer, you can also use "Receive Messages" with "Receive and Delete" option. There's a tracking issue to support this issue server side: https://github.com/Azure/azure-service-bus/issues/1 — Sean Feldman, Oct 25 '17 at 03:13

score 9 · Accepted Answer · answered Oct 25 '17 at 02:43

You can most certainly do it via code. If you're using Service Bus SDK, you could do something like the following:

    static void PurgeMessagesFromSubscription()
    {
        var connectionString = "Endpoint=sb://account-name.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=access key";
        var topic = "topic-name";
        var subscription = "subscription-name";
        int batchSize = 100;
        var subscriptionClient = SubscriptionClient.CreateFromConnectionString(connectionString, topic, subscription, ReceiveMode.ReceiveAndDelete);
        do
        {
            var messages = subscriptionClient.ReceiveBatch(batchSize);
            if (messages.Count() == 0)
            {
                break;
            }
        }
        while (true);
    }

What this code will do is fetch messages from the subscription (100 at a time) in Receive & Delete mode so that as soon as messages are fetched, they are deleted from the subscription automatically.

I believe Service Bus Explorer tool also has the capability to purge messages. You can use that as well instead of writing the code.

Looks good. BTW is there also way to delete specific message in service bus topic subscription? — Rajat Arora, May 06 '20 at 15:13

score 3 · Answer 2 · answered Oct 25 '17 at 05:58

3

If you have a lot of messages and can tolerate a bit of downtime on subscriber side, it might be faster to just drop the subscription and create a new one with the same name.

answered Oct 25 '17 at 05:58

Mikhail Shilkov

34,128
3
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This is interesting! Do you know how much time does Azure Service Bus takes to delete a subscription? From my experience with Storage Queues, it may take up to 30 seconds or more for a queue to get actually deleted before which you can create a new queue with the same name. – Gaurav Mantri Oct 25 '17 at 06:49
I don't have any formal timings, but I did it several times and it seemed pretty much instantaneous. – Mikhail Shilkov Oct 25 '17 at 07:10
How do you do so through code in a ASP.NET Core application? – droft1312 Nov 26 '19 at 15:23

score 0 · Answer 3 · edited Jan 11 '23 at 14:43

Thank you @Gaurav Mantri, I used slightly changed code without the batch option with version 5.2.0 of Microsoft.Azure.ServiceBus Nuget Package:

var connectionString = "Endpoint=sb://";
var topic = "topic";
var subscription = "subscription";
var subscriptionClient = new SubscriptionClient(connectionString, topic, subscription, ReceiveMode.ReceiveAndDelete);

subscriptionClient.RegisterMessageHandler(
  (message, token) =>
    {
     Console.WriteLine($"Received message: SequenceNumber: 
             {message.SystemProperties.SequenceNumber}");

      return Task.CompletedTask;
     },
   (exceptionEvent) =>
    {
     Console.WriteLine("Exception = " + exceptionEvent.Exception);
     return Task.CompletedTask;
    });

How to purge messages for Service Bus Topic Subscription

3 Answers3

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