Board Review: Service Bus: Introductory session with champion scenarios

[ramya-rao-a]

The Basics

• Team responsible for the client library: Azure SDK team

• Link to documentation describing the service:

  • Top level docs
    • What is Azure Service Bus
    • Service Bus Queues, Topics & Subscriptions
    • Compare the 3 Azure Messaging solutions
    • Compare Storage Queue & Service Bus Queues
    • Choose the right Messaging Service for your needs
    • Two different modes of receiving messages in Service Bus
    • Messages, Payload & Serialiazation
  • Client Implementation details
    • AMQP in Service Bus
    • More AMQP in Service Bus
    • Simulate request/response pattern in AMQP
    • Spec for request/response features in ServiceBus that follows the previous point
    • AMQP spec

• Contact email:

  • PM: Ashish Chhabria
  • Dev Lead: Shankar Reddy Sama

Champion Scenarios

Service Bus is intended for traditional enterprise applications. These enterprise applications require transactions, ordering, duplicate detection, and instantaneous consistency. Service Bus enables cloud-native applications to provide reliable state transition management for business processes. When handling high-value messages that cannot be lost or duplicated, use Azure Service Bus. Service Bus also facilitates highly secure communication across hybrid cloud solutions and can connect existing on-premises systems to cloud solutions.

Service Bus is a brokered messaging system. It stores messages in a "broker" (for example, a queue) until the consuming party is ready to receive the messages.

It has the following characteristics:

• reliable asynchronous message delivery (enterprise messaging as a service) that requires polling
• advanced messaging features like FIFO, batching/sessions, transactions, dead-lettering, temporal control, routing and filtering, and duplicate detection
• at least once delivery
• optional in-order delivery

Some sample scenarios

• Order processing
• Financial transactions

[adrianhall]

Scheduled for the 18th

[richardpark-msft]

Scenario:

Service bus used for resiliency ("no lost messages"), allowing for backpressure
and coordination with an external system.

1. An external system (Azure DevOps) generates events for a repo (ex: pull request created).
   The code that generates these messages is pre-canned and not under user control.
2. The events are sent to a single queue, which is configured to auto-forward to a topic.
3. That topic is subscribed to by multiple Azure Functions:
   • A telemetry function that forwards data to appinsights with no throttling.
   • A status function that updates a SQL Server database that users view (through a webpage)
     to see which builds are active and where.
   • A build function that launches jobs in a datacenter with more capable hardware.
     • This function cancels messages when it detects too much activity to prevent
       overwhelming the remote service which can

[richardpark-msft]

Scenario:

Service bus coordinates work between several components which are in various languages and platforms:

• Mobile (Android, IOS)
• Desktop (Linux, Windows)
• Web

Several key parts of this design:

• Disparate systems can make tracing and debugging difficult. Not only working with multiple programs but multiple groups.
• Network connectivity can be erratic - user needs some form of local buffering to handle "outboxing" a message which will get sent when the network comes back up.
• Some services send messages but infrequently - sometimes just once a day.

[ramya-rao-a]

Some more helpful links from Clemens

• Messaging Patterns
• More on choosing messaging service from an architecture perspective

[ramya-rao-a]

cc @KieranBrantnerMagee, @JoshLove-msft, @hemanttanwar, @richardpark-msft, @HarshaNalluru, @ShivangiReja, @yunhaoling, @srnagar

[kyle-patterson]

The recording is available here (MSFT INTERNAL): https://msit.microsoftstream.com/video/0222fec8-2c36-4db3-a710-74ed2811454f

.NET Samples are available here: https://github.com/Azure/azure-service-bus/tree/master/samples/DotNet/Microsoft.Azure.ServiceBus