How to purge a Azure ServiceBus Topics Subscrption in C# (Microsoft.Azure.ServiceBus v3+)?

Question

How can I (in C#) purge an Azure service bus's topic subscription using the Microsoft.Azure.ServiceBus package (version 3+)?

I am aware of SO question. But the selected answer seems to use ReceiveBatch() on SubscriptionClient which does not appear to be available anymore(?). SubscriptionClient only really seems to now have RegisterMessageHandler() to handle messages, however using this means my client would never know when the subsciption is actually empty.

Is there a clean way to purge a topic using C#?

score 2 · Accepted Answer · edited Jun 04 '18 at 15:28

2

You can use MessageReceiver class in similar manner:

IMessageReceiver messageReceiver = new MessageReceiver(
    namespaceConnectionString,
    EntityNameHelper.FormatSubscriptionPath(topicName, subscriptionName),
    ReceiveMode.ReceiveAndDelete);

int batchSize = 100;
var operationTimeout = TimeSpan.FromSeconds(3);

do
{
    var messages = await messageReceiver.ReceiveAsync(batchSize, operationTimeout);
    if (messages == null || messages.Count == 0) // Returns null if no message is found
    {
       break;
    }
}
while (true);

Note that only async API is now available.

edited Jun 04 '18 at 15:28

bytedev

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answered Jun 04 '18 at 10:26

Mikhail Shilkov

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ReceiveAsync often keeps returning null for me. Are you aware of any reasons it might do this? – bytedev Jun 04 '18 at 14:10
@nashwan Docs say "Returns null if no message is found", so yes, I updated my answer – Mikhail Shilkov Jun 04 '18 at 14:26
yeah thought so :-). Also you can use .Count as IList is returned from ReceiveAsync. In my code I also added operationTimeout of a few seconds when calling ReceiveAsync otherwise I can be waiting quite a while for it to finish. – bytedev Jun 04 '18 at 15:09
@nashwan Great! Feel free to edit my answer with your final code. – Mikhail Shilkov Jun 04 '18 at 15:10
done. IMO you can also just use a while(true) no need for do/while... but then thats just a matter of taste I guess :-) – bytedev Jun 04 '18 at 15:14
Thanks. True, I copied do-while from the original answer. – Mikhail Shilkov Jun 04 '18 at 15:29
As a side note, you may also close the `MessageReceiver` – Loul G. Oct 21 '19 at 10:20

How to purge a Azure ServiceBus Topics Subscrption in C# (Microsoft.Azure.ServiceBus v3+)?

1 Answers1