Topic Isolation - (Part 6) Testing the limits of Windows Azure Service Bus

Some time ago I wrote about how I manage to process millions of messages over Windows Azure Service Bus. I discover that processing millions of messages every hour will increase the latency and response time of our topic.

I wanted to find out what I happening with the topics from the same account and data center when the load of one of them increase drastically. 

To be able to make this tests and discover the answer to my questions I made the following setup:

• Create 3 topics on the same data center. Two on the same account and another one on a different account.
• Create a worker role that will read messages from topics (via subscription) and monitor the delay time. The results will be written to Windows Azure Tables.
• Create 8 worker roles that will push hundreds of thousands of messages in a very short period of time on the same topic (multi-threading rules).
• Create 4 worker roles that will consume messages from our topic (via subscription).

In the end we end up with 12 worker roles that hit the same topic. Of course the latency of that topic increases, but we wanted to see if the rest of the topics are affected. I run this performance test for around 6 hours and …

The results of the test were extremely good. The second and 3rd topic where not affected by this load test. The latency remain the same for this 2 topics during the load test.

I’m very happy with this results. This is a confirmation that we will have a good performance on all of our topics. The topics are 100% isolated are not affected by the rest of out topics.