Azure Service Bus incoming requests when nothing running

Question

I have a namespace in ASB with a single topic and subscription. I can see the message count from when I was testing the consumer (ruby client), the first spike, but after I stopped testing and nothing in the client was running there were 10 incoming requests from 'somewhere'. The second spike in the graph. The machine was off at this point so it must have come from Azure.

Within half an hour of turning on my machine there were 6 incoming requests, the third spike but nothing is running as it's a commandline client so I assume it's Azure again.

I don't have anything else in Azure (functions apps etc). Literally nothing is running/polling/pulling/peeking etc.

Is it possible to identify where these requests are coming from? Graph is below.

Answer 1

Incoming requests are not incoming messages. When there are no messaging and you receive nothing, there are still operations taking place. This is due to the fact that the client (assuming you're using client with a message handler rather than trying to retrieve messages yourself), the client is performing long-polling. I.e. the client will poll for new messages rather than the broker to push those. Unlike RabbitMQ, which will push to a client when messages become available.