Added handler for removing orphaned subscriptions

src/bundles/Elsa.ServerAndStudio.Web/Program.cs

@@ -47,7 +47,25 @@ services
 
         if (useMassTransit)
         {
-            elsa.UseMassTransit();
+            elsa.UseMassTransit(massTransit =>
+                massTransit.UseAzureServiceBus(azureServiceBusConnectionString, serviceBusFeature => serviceBusFeature.ConfigureServiceBus = bus =>
+                {
+                    bus.PrefetchCount = 4;
+                    bus.LockDuration = TimeSpan.FromMinutes(5);
+                    bus.MaxConcurrentCalls = 32;
+                    bus.MaxDeliveryCount = 8;
+                    // etc.
+                })
+            // massTransit.UseRabbitMq(rabbitMqConnectionString, rabbit => rabbit.ConfigureServiceBus = bus =>
+            //     {
+            //         bus.PrefetchCount = 4;
+            //         bus.Durable = true;
+            //         bus.AutoDelete = false;
+            //         bus.ConcurrentMessageLimit = 32;
+            //         // etc.
+            //     }))
+            );
+
         }
     });
 

src/modules/Elsa.MassTransit.AzureServiceBus/Extensions/ModuleExtensions.cs

@@ -22,6 +22,7 @@ public static class ModuleExtensions
 
         void Configure(AzureServiceBusFeature bus)
         {
+            bus.AzureServiceBusOptions = options => options.ConnectionStringOrName = connectionString;
             bus.ConnectionString = connectionString;
             configure?.Invoke(bus);
         }

src/modules/Elsa.MassTransit.AzureServiceBus/Features/AzureServiceBusFeature.cs

@@ -36,6 +36,11 @@ public class AzureServiceBusFeature : FeatureBase
     /// </summary>
     public Action<IServiceBusBusFactoryConfigurator>? ConfigureServiceBus { get; set; }
     
+    /// <summary>
+    /// A delegate to configure <see cref="AzureServiceBusOptions"/>.
+    /// </summary>
+    public Action<AzureServiceBusOptions> AzureServiceBusOptions { get; set; } = _ => { };
+    
     /// <summary>
     /// A delegate to create a <see cref="ServiceBusAdministrationClient"/> instance.
     /// </summary>
@@ -98,7 +103,9 @@ public class AzureServiceBusFeature : FeatureBase
                 }
 
                 var genericType = consumerInterface.GetGenericArguments()[0];
-                var topicName = $"{genericType.Namespace.ToLower()}~{genericType.Name.ToLower()}";
+                //While the name might show up in the Azure portal with a ~, the separator is actually an /
+                //see https://learn.microsoft.com/en-us/archive/blogs/servicebus/azure-service-bus-azure-resource-manager-and-this-character
+                var topicName = $"{genericType.Namespace.ToLower()}/{genericType.Name.ToLower()}";
                     
                 subscriptionTopology.Add(new MessageSubscriptionTopology(topicName,
                     consumer.Name ?? genericType.Name.ToLower(),
@@ -112,6 +119,7 @@ public class AzureServiceBusFeature : FeatureBase
     /// <inheritdoc />
     public override void Apply()
     {
+        Services.Configure(AzureServiceBusOptions);
         Services.AddScoped(ServiceBusAdministrationClientFactory);
         Services.AddNotificationHandler<OrphanedSubscriptionRemover>();
     }

src/modules/Elsa.MassTransit.AzureServiceBus/Handlers/OrphanedSubscriptionRemover.cs

@@ -8,7 +8,9 @@ namespace Elsa.MassTransit.AzureServiceBus.Handlers;
 /// <summary>
 /// Class responsible for removing orphaned subscriptions.
 /// </summary>
-public class OrphanedSubscriptionRemover(MessageTopologyProvider topologyProvider, ServiceBusAdministrationClient client) 
+public class OrphanedSubscriptionRemover(
+    MessageTopologyProvider topologyProvider,
+    ServiceBusAdministrationClient client)
     : INotificationHandler<InstanceDeactivated>
 {
     /// <summary>
@@ -16,13 +18,26 @@ public class OrphanedSubscriptionRemover(MessageTopologyProvider topologyProvide
     /// </summary>
     public async Task HandleAsync(InstanceDeactivated notification, CancellationToken cancellationToken)
     {
-        var subscriptions = topologyProvider.GetShortLivedSubscriptions().ToList();
-        
-        foreach (var subscription in subscriptions)
+        var subscriptionTopology = topologyProvider.GetShortLivedSubscriptions().ToList();
+
+        foreach (var subscription in subscriptionTopology)
         {
-            await client.DeleteSubscriptionAsync(subscription.TopicName,
-                $"Elsa-{notification.InstanceName}-{subscription.SubscriptionName}",
-                cancellationToken);
+            // Get subscriptions based on topics instead of the topology since when names are longer than 50 characters
+            // MassTransit automatically truncates them.
+            await foreach (var asbSubscription in client.GetSubscriptionsAsync(subscription.TopicName,
+                               cancellationToken))
+            {
+                if (asbSubscription.SubscriptionName.StartsWith($"Elsa-{notification.InstanceName}-"))
+                {
+                    var queueName = asbSubscription.ForwardTo.Substring(asbSubscription.ForwardTo.LastIndexOf('/') + 1);
+
+                    await Task.WhenAll(
+                        client.DeleteSubscriptionAsync(subscription.TopicName,
+                            asbSubscription.SubscriptionName,
+                            cancellationToken),
+                        client.DeleteQueueAsync(queueName, cancellationToken));
+                }
+            }
         }
     }
 }

src/modules/Elsa.MassTransit.AzureServiceBus/Options/AzureServiceBusOptions.cs

@@ -8,5 +8,5 @@ public class AzureServiceBusOptions
     /// <summary>
     /// Th connection string or connection string name to connect with the service bus.
     /// </summary>
-    public string ConnectionStringOrName { get; set; } = default!;
+    public string? ConnectionStringOrName { get; set; }
 }