i am using azure service bus's topic and subscribers. Out of 3 subscribers only one gets messages rest two are receiving every other message

Question

I am publishing messages to Azure service topic which has 3 subscribers. I am using Microsoft.Azure.ServiceBus and its topic client and subscription client classes. For some reason two out of 3 subscribers are receiving every other message.

I am using this article to setup subscribers https://damienbod.com/2019/04/24/using-azure-service-bus-topics-in-asp-net-core/

Any ideas about where to look for the issue will be very helpful

Answer 1

As mentioned by @Gaurav the suggestion would be verifying the SQL filter. By default when you create the subscription you will see "$Default" SQL filter with the expression as 1=1 means that it will accept every message that are send. You can either use service bus explorer or navigation to your subscription in the azure portal to verify the SQL filter.

Answer 2

Out of 3 subscribers only one gets messages rest two are receiving every other message

This will happen if all the subscription clients are wired to the same subscription. Each message will be received by only one of the subscription clients and will be completed after processing.