[SOT322] Serverless Side-by-Side Extensions with Azure Durable Functions - When stateful meets stateless
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The document discusses the integration of serverless architecture with Azure Durable Functions, highlighting their advantages, such as state management and simplified orchestration. It outlines the challenges associated with Functions as a Service (FaaS) and presents Durable Functions as a solution for modeling complex workflows. Additionally, it provides insights on local development and references resources for further exploration.
[SOT322] Serverless Side-by-Side Extensions with Azure Durable Functions - When stateful meets stateless
- 1. info@minnosphere.comwww.minnosphere.com Serverless Side-by-Side Extensions with Azure Durable Functions When stateful meets stateless
- 2. © minnosphere 2020 | Azure Durable Functions 2 About me • Heading the Microsoft Azure team@minnosphere • In the SAP ecosystem since 2005 • Kind of active in the community • Focus Topics: Extensibility, Cloud Native Development, Serverless • @lechnerc77
- 3. © minnosphere 2020 | Azure Durable Functions 3 Why should we care about Microsoft at all? Lift Enabling Data First Execution Reshape Enhancing Processes with Intelligence and Automation Create Creating Experiences with New Business Models
- 4. © minnosphere 2020 | Azure Durable Functions 4 Scenario – Serverless Extension of SAP https://blogs.sap.com/2019/12/09/a-serverless-extension-story-from-abap-to-azure/
- 5. © minnosphere 2020 | Azure Durable Functions 5 Azure Functions 101
- 6. © minnosphere 2020 | Azure Durable Functions 6 Principles and Best Practices Serverless is great … but Functions as a Service come with “drawbacks” • Functions must be stateless • Functions must not call other functions • Functions should do only one thing
- 7. © minnosphere 2020 | Azure Durable Functions 7 How do we model “workflows” in a FaaS world?
- 8. © minnosphere 2020 | Azure Durable Functions 8 Function Chaining to achieve State Function 1 Function 2 Function 3 Problems • Unclear relation between functions • Queues are a necessary evil • Context must be stored in a DB • Error handling becomes very complex
- 9. © minnosphere 2020 | Azure Durable Functions 9 Durable Functions for the Rescue • Extension to the Azure Functions Framework • Preserves local state via Event Sourcing • Heavy work happens behind the curtain • Supports you in front of the curtain with additional features
- 10. © minnosphere 2020 | Azure Durable Functions 10 How does this work? Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 11. © minnosphere 2020 | Azure Durable Functions 11 How does this work? Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 12. © minnosphere 2020 | Azure Durable Functions 12 Step 1 - Trigger Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 13. © minnosphere 2020 | Azure Durable Functions 13 Step 2 – Orchestrator fetches event & schedules task for F1 Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 14. © minnosphere 2020 | Azure Durable Functions 14 Step 3 – F1 executes task & returns result Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 15. © minnosphere 2020 | Azure Durable Functions 15 Step 4a – Orchestrator updates Event History Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 16. © minnosphere 2020 | Azure Durable Functions 16 Step 4b – Orchestrator schedules next task Event History Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 17. © minnosphere 2020 | Azure Durable Functions 17 Step 4b – Orchestrator schedules next task Event History Trigger Orchestrator Activity Tasks in orchestrator 1. let x = await ctx.CallActivityAsync(“F1”) 2. let y = await ctx.CallActivityAsync(“F2”, x) 3. return await ctx.CallActivityAsync(“F3”, y)
- 18. © minnosphere 2020 | Azure Durable Functions 18 Summing up: Durable Functions are like …
- 19. © minnosphere 2020 | Azure Durable Functions 19 Let’s get local • Azure Functions Runtime (https://docs.microsoft.com/en-US/azure/azure-functions/functions-run-local?tabs=windows) • Azure Durable Functions Extension (npm install durable-functions) • Microsoft SQL Server Express (https://www.microsoft.com/de-de/sql-server/sql-server-downloads) • Microsoft Azure Storage Emulator (https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/storage/common/storage-use- emulator.md) • Optional: Microsoft Azure Storage Explorer (https://azure.microsoft.com/en-us/features/storage-explorer/) Walkthrough: https://youtu.be/HdhPC_K6cLo
- 20. © minnosphere 2020 | Azure Durable Functions 20 Challenge 1 – Decompose Single Function into Orchestrator and Activities SAP Cloud Applications Current State Activity 2x Target State Orchestrator Activity 1 Activity 2 SAP Cloud Applications
- 21. © minnosphere 2020 | Azure Durable Functions 21 Challenge 2 – Handle Errors in Activity Calls (Retry) Orchestrator Activity 1 Activity 2 SAP Cloud Applications
- 22. © minnosphere 2020 | Azure Durable Functions 22 Challenge 3 – Handle Timeouts in Activity Calls Orchestrator Activity 1 Activity 2 SAP Cloud Applications Race Condition
- 23. Orchestrator 3 Activity 1 Activity 2 SAP Cloud Applications © minnosphere 2020 | Azure Durable Functions 23 Challenge 4 – Scale Out … Do we have an external State? Orchestrator 2 Activity 1 Activity 2 SAP Cloud Applications Orchestrator 1 Activity 1 Activity 2 SAP Cloud Applications Circuit Breaker
- 24. © minnosphere 2020 | Azure Durable Functions 24 Summary - Durable Functions • … are a great AddOn to Azure Functions • … allow the modelling of complex scenarios without losing the benefits of FaaS • … manage state for you • … low entry barrier due to support of local development • … open up new options in the context of side-by-side extensibility
- 25. Thank you for your attention © minnosphere 2020 | Azure Durable Functions25
- 26. minnosphere GmbH Robert-Buerkle-Str. 1, 85737 Ismaning/Munich Germany www.minnosphere.com Dr. Christian Lechner christian.lechner@minnosphere.com
- 27. © minnosphere 2020 | Azure Durable Functions 27 Additional Resources SAP Embrace – my 5 cent • https://blogs.sap.com/2020/01/29/my-thoughts-on-sap-embrace-part-1/ • https://blogs.sap.com/2020/01/29/my-thoughts-on-sap-embrace-part-2/ Serverless Extensions with Microsoft Azure • https://blogs.sap.com/2019/12/09/a-serverless-extension-story-from-abap-to-azure/ • https://blogs.sap.com/2020/02/17/a-serverless-extension-story-ii-bringing-state-to-the-stateless/ GitHub Repo • https://github.com/lechnerc77/AzureFuncPurchaseOrderCheckDemo Walk Through Local Development with Azure Durable Functions: • https://youtu.be/HdhPC_K6cLo