About SLAs for Azure Service Bus

Question

The Azure Service Bus (ASB) is listed as having a 99.9% monthly uptime percentage.
https://azure.microsoft.com/en-us/support/legal/sla/service-bus/v1_1/

On the other hand, ASB also has a feature called active replication.
https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-outages-disasters#active-replication

If I use this feature, would the monthly uptime percentage be 99.9% * 99.9%?
Or is it still the same, 99.9%?

Answer 1

@Kazuto Tateyama Thanks for reaching out. The active replication is the client side approach against datacenter outages when using the standard messaging.
This means that you will have two standard namespace and your client code will be sending/consuming the messages from both the namespace. A client receives messages from both queues. The receiver processes the first copy of a message, and the second copy is suppressed. For more details on the code end you can refer to this sample.

This is not the feature of the service bus but the client side approach that can help you with the availability when there is data center/backend issue.
Azure guarantee for Service Bus Queues and Topics is same i.e. at least 99.9% of the time, properly configured applications will be able to send or receive messages as documented here.
The SLA is calculated at the subscription level and for more details please refer to The SLA details section here.

Answer 2

Hi @Kazuto Tateyama

The monthly uptime percentage (at least) is going to be 99.9%. This means that Azure will guarantee 99.9% uptime for properly configured Azure Service Buses.

If it is any less, here is the credit you will receive if they are down any longer than 99.9%:

Cited from https://azure.microsoft.com/en-us/support/legal/sla/service-bus/v1_1/

If you have any further questions I would suggest reaching out to Azure Sales:

https://azure.microsoft.com/en-us/contact/

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