Introduction to Azure Service Bus

Develop Azure Event-based and Message-based Solutions

Fiodar Sazanavets

Senior Software Engineer and Microsoft MVP

Queue Storage vs Service Bus

Queue Storage

Service Bus

Queue Storage

Service Bus

Point-to-point:
- Once producer sends a message
- One consumer picks it up
- Message processed once
Similar to how Queue Storage works

Service Bus logo

Publish-subscribe model
- Multiple producers send messages
- Multiple consumers can received the same message
Each subscription can filter messages:
- Each subscription gets what's relevant
A queue is like a single inbox
A topic is like a mailing list

Service Bus Topic

Message reliability

Duplicate detection prevents messages from being processed twice.
If a sender retries and the same message arrives again, it is detected by its message ID.
Duplicates are discarded within a configured time window.
This helps achieve near exactly-once processing despite network retries.

Service Bus duplicate detection

Service Bus Sessions

Service Bus Sessions enable ordered message processing.
Related messages share a Session ID (for example, all updates for the same order).
Each session is delivered to one consumer at a time.
Message order is preserved within a session, and the consumer can keep lightweight state.
Multiple sessions can be processed in parallel, while each session remains ordered.

Develop Azure Event-based and Message-based Solutions