public static async Task Handle(DroppedSubscription subscription, Func <Task> compensatingAction)
{
var message = subscription.ExceptionMessage;
var retryPolicy = subscription.RetryPolicy;
switch (subscription.DropReason)
{
case SubscriptionDropReason.UserInitiated:
//the client called Close() on the subscription
log.Info($@"Subscription to {subscription.StreamId} was closed by the client.
{message}");
break;
case SubscriptionDropReason.NotAuthenticated:
//the client is not authenticated -> check ACL
log.Error($@"Subscription to {subscription.StreamId} was dropped because the client could not be authenticated.
Check the Access Control List. {message}");
break;
case SubscriptionDropReason.AccessDenied:
//access to the stream was denied -> check ACL
log.Error($@"Subscription to {subscription.StreamId} was dropped because the client was denied access.
Check the Access Control List. {message}");
break;
case SubscriptionDropReason.SubscribingError:
//something went wrong while subscribing - retry
log.Error($@"Subscription to {subscription.StreamId} failed.
{message}");
await RetrySubscriptionAsync(compensatingAction, retryPolicy).ConfigureAwait(false);
break;
case SubscriptionDropReason.ServerError:
//error on the server
log.Error($@"A server error occurred which dropped the subscription to {subscription.StreamId}
{message}");
break;
case SubscriptionDropReason.ConnectionClosed:
//the connection was closed - retry
log.Error($@"Subscription to {subscription.StreamId} was dropped due to the connection being closed.
{message}");
await RetrySubscriptionAsync(compensatingAction, retryPolicy).ConfigureAwait(false);
break;
case SubscriptionDropReason.CatchUpError:
//an error occurred during the catch-up phase - retry
log.Error($@"Subscription to {subscription.StreamId} was dropped during the catch-up phase.
{message}");
await RetrySubscriptionAsync(compensatingAction, retryPolicy).ConfigureAwait(false);
break;
case SubscriptionDropReason.ProcessingQueueOverflow:
//occurs when the number of events on the push buffer exceed the specified maximum - retry
log.Warn($@"Subscription to {subscription.StreamId} was dropped due to a processing buffer overflow.
{message}");
await RetrySubscriptionAsync(compensatingAction, retryPolicy).ConfigureAwait(false);
break;
case SubscriptionDropReason.EventHandlerException:
//Subscription dropped because an exception was thrown by one of our handlers.
log.Error($@"Subscription to {subscription.StreamId} was dropped in response to a handler exception.
{message}");
break;
case SubscriptionDropReason.MaxSubscribersReached:
//The maximum number of subscribers for the persistent subscription has been reached
log.Error($@"Subscription to {subscription.StreamId} was dropped because the maximum no. of subscribers was reached.
{message}");
break;
case SubscriptionDropReason.PersistentSubscriptionDeleted:
//The persistent subscription has been deleted
log.Error($@"The persistent subscription to {subscription.StreamId} was dropped because it was deleted.
{message}");
break;
case SubscriptionDropReason.Unknown:
//Scoobied
log.Error($@"Subscription to {subscription.StreamId} was dropped for an unspecified reason.
{message}");
break;
case SubscriptionDropReason.NotFound:
//Target of persistent subscription was not found. Needs to be created first
log.Error($@"The persistent subscription to {subscription.StreamId} could not be found.
{message}");
break;
default:
throw new ArgumentOutOfRangeException(nameof(subscription.DropReason), subscription.DropReason, null);
}
}
private async Task SubscriptionDropped(EventStoreSubscription subscription, SubscriptionDropReason dropReason, Exception exception)
{
var subscriptionDropped = new DroppedSubscription(this.subscription, exception.Message, dropReason);
await HandleDroppedSubscription(subscriptionDropped);
}
private async Task SubscriptionDropped(EventStorePersistentSubscriptionBase subscriptionBase, SubscriptionDropReason dropReason, Exception exception)
{
var subscriptionDropped = new DroppedSubscription(subscription, exception.Message, dropReason);
await HandleDroppedSubscription(subscriptionDropped);
}
protected async Task HandleDroppedSubscription(DroppedSubscription subscriptionDropped) => await DroppedSubscriptionPolicy.Handle(subscriptionDropped, async() => await ConnectToSubscription(subscription));