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azure-logic-appsazureservicebusazure-logic-app-standard

Logic app standard - service bus session problems

I have an azure logic app standard application. This has two workflows; RunBre and StubSatellite.

The desired interaction flow is illustrated in the following diagram:

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The RunBre workflow generates a guid as a session id. It then publishes this to the service bus topic:

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This message is being correctly consumed by the StubSatellite workflow:

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From checking the logic app the run history and service bus explorer, I can see that a message with the same session id generated by RunBre is correctly being published to the response-queue by the StubSatellite workflow. Also, the service bus explore shows an active session on the response queue, with the correct session id.

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My problem comes when the RunBre workflow attempts to consume the response message from the queue. I'm using the built-in action "Get messages from a queue session". I'm passing it the correct sessionId as a parameter but it's throwing the following error:

{
  "code": "ServiceProviderActionFailed",
  "message": "The service provider action failed with error code 'ServiceOperationFailed' and error message 'The Service Bus session was not found to perform operation 'getMessagesFromQueueSession' on session id '30cb936a-4e11-4126-8047-4ac6f4b876b8'.'."
}

I think the reason for the error is that the session aware action "Get messages from a queue session" can only be used in a workflow that's triggered by a session aware trigger such as "On single new message from queue session". However, this is not possible in my scenario. I need to support the following:

http client --sync request--> logic app process manager --> svc bus topic --> logic app worker --> service bus queue --> logic app process manager --sync response--> http client

Solution

  • It turns out what I was trying to do is not possible using the new session aware actions. They will only work in a workflow that's triggered by one of the new session aware triggers - details here

    As a work-around, I added a local function that uses the Azure.Messaging.ServiceBus nuget package to read from the session queue:

    var client = new ServiceBusClient(serviceBusNamespace, credential);

var receiver = await client.AcceptSessionAsync(queueName, sessionId);
ServiceBusReceivedMessage message = await receiver.ReceiveMessageAsync();