How to broadcast a message to multiple nodes?

[lukedukeus]

I have a small demo working where I am sending messages with PostAsync, and another node recieves the messages. This all works well, but if I add another node that is also listening for messages, then each of the two listening nodes only gets every other message. Instead, I would like a message to be broadcasted to and handled by all nodes.

I am using rabbitmq for the transport, and configuring it like this:

            var connection = new RmqMessagingGatewayConnection
            {
                AmpqUri = new AmqpUriSpecification(ampqUri),
                Exchange = new Exchange("messaging.exchange", ExchangeType.Fanout)
            };

            var publications = GetPublications();
            var subscriptions = GetSubscriptions();

            var producerFactory = new RmqProducerRegistryFactory(connection, publications);
            var consumerFactory = new RmqMessageConsumerFactory(connection);

            services
                .AddHostedService<ServiceActivatorHostedService>()
                .AddServiceActivator(opt =>
                {
                    opt.Subscriptions = subscriptions;

                    opt.ChannelFactory = new ChannelFactory(consumerFactory);
                })
                .MapperRegistry(options =>
                {
                    options.Register<EventsOccurredEvent, ProtobufMessageMapper<EventsOccurredEvent>>();
                }).AsyncHandlers(options =>
                {
                    options.RegisterAsync<EventsOccurredEvent, EventsHandler>();
                })
                .UseExternalBus(producerFactory.Create());

        private static RmqPublication[] GetPublications()
        {
            return [
                new RmqPublication
                {
                    MakeChannels = OnMissingChannel.Create,
                    Topic = new RoutingKey(nameof(EventsOccurredEvent)),
                },
            ];
        }

        private static RmqSubscription[] GetSubscriptions()
        {
            return [
                new RmqSubscription<EventsOccurredEvent>(
                    new SubscriptionName(nameof(EventsOccurredEvent)),
                    new ChannelName(nameof(EventsOccurredEvent)),
                    new RoutingKey(nameof(EventsOccurredEvent)),
                    makeChannels: OnMissingChannel.Create,
                    runAsync: true
                )
            ];
        }

[lukedukeus]

I found out the subscription names have to be unique. For me the workaround was changing new SubscriptionName(nameof(EventsOccurredEvent)) to new SubscriptionName($"{nameof(EventsOccurredEvent)}-{Guid.CreateVersion7()}")