Help! I've created a serverless monolith! - CloudBrew

Slides for my CloudBrew 2022 session.
I talked about serverless monoliths, how unmaintainable apps cause problems with agility and how to measure agility. How accidental complexity can be reduced or moved, and I offered three strategies how to breakup a serverless monolith based on, bounded context, resilience, and scalability.

Transcript

1. @MarcDuiker
2. @MarcDuiker 2 Marc Duiker Sr Developer Advocate
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9. @MarcDuiker 9 https://en.wikipedia.org/wiki/Monolithic_application “In software engineering, a monolithic application describes a software application that is designed without modularity.”
10. @MarcDuiker 10 https://en.wikipedia.org/wiki/Modularity “…modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use.”
11. @MarcDuiker 11 App Server DB Server
12. @MarcDuiker 12 Function App Function App Queue Storage
13. @MarcDuiker 13 Function App Function App Queue Storage
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18. @MarcDuiker 18 https://martinfowler.com/articles/agileStory.html “We eventually agreed on "agile" as we felt that captured the adaptiveness and response to change which we felt was so important to our approach…”
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25. @MarcDuiker 25 Task on backlog Work started Work completed
26. @MarcDuiker 26 https://www.atlassian.com/incident-management/kpis/common-metrics
27. @MarcDuiker 27 https://www.atlassian.com/incident-management/kpis/common-metrics
28. @MarcDuiker 28 https://www.atlassian.com/incident-management/kpis/common-metrics
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31. @MarcDuiker 31 https://learn.microsoft.com/en-us/azure/azure-functions/functions-host-json
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33. @MarcDuiker 33 https://learn.microsoft.com/en-us/azure/azure-functions/functions-deployment-slots
34. @MarcDuiker 34 Function App Website Queue
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37. @MarcDuiker 37 Caused by the nature of the (business) problem. Can’t be easily reduced. Caused by decisions we make related to architecture, frameworks, packages, code style etc. Can be reduced. https://en.wikipedia.org/wiki/Programming_complexity
38. @MarcDuiker 38 https://en.wikipedia.org/wiki/Programming_complexity Caused by decisions we make related to architecture, frameworks, packages, code style etc. Can be reduced. Caused by the nature of the (business) problem. Can’t be easily reduced.
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49. @MarcDuiker 49 public static class ChainingExample { [FunctionName(nameof(ChainingExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityAsync<string>( nameof(ActivityFunctionA), null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
50. @MarcDuiker 50 public static class ChainingExample { [FunctionName(nameof(ChainingExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityAsync<string>( nameof(ActivityFunctionA), null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
51. @MarcDuiker 51 public static class ChainingExample { [FunctionName(nameof(ChainingExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityAsync<string>( nameof(ActivityFunctionA), null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
52. @MarcDuiker 52 public static class ChainingExample { [FunctionName(nameof(ChainingExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityAsync<string>( nameof(ActivityFunctionA), null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
53. @MarcDuiker 53 public static class ChainingExample { [FunctionName(nameof(ChainingExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityAsync<string>( nameof(ActivityFunctionA), null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
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55. @MarcDuiker 55 public static class FanOutFanInExample { [FunctionName(nameof(FanOutFanInExample))] public static async Task<string[]> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var tasks = new List<Task<string>>(); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionA), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionB), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionC), null)); var results = await Task.WhenAll(tasks); return results; }
56. @MarcDuiker 56 public static class FanOutFanInExample { [FunctionName(nameof(FanOutFanInExample))] public static async Task<string[]> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var tasks = new List<Task<string>>(); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionA), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionB), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionC), null)); var results = await Task.WhenAll(tasks); return results; }
57. @MarcDuiker 57 public static class FanOutFanInExample { [FunctionName(nameof(FanOutFanInExample))] public static async Task<string[]> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var tasks = new List<Task<string>>(); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionA), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionB), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionC), null)); var results = await Task.WhenAll(tasks); return results; }
58. @MarcDuiker 58 public static class FanOutFanInExample { [FunctionName(nameof(FanOutFanInExample))] public static async Task<string[]> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var tasks = new List<Task<string>>(); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionA), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionB), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionC), null)); var results = await Task.WhenAll(tasks); return results; }
59. @MarcDuiker 59 public static class FanOutFanInExample { [FunctionName(nameof(FanOutFanInExample))] public static async Task<string[]> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var tasks = new List<Task<string>>(); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionA), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionB), null)); tasks.Add(context.CallActivityAsync<string>( nameof(ActivityFunctionC), null)); var results = await Task.WhenAll(tasks); return results; }
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61. @MarcDuiker 61 public static class SubOrchestratorExample { [FunctionName(nameof(SubOrchestratorExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallSubOrchestratorAsync<string>( nameof(SubOrchestratorA), null); var resultB = await context.CallSubOrchestratorAsync<string>( nameof(SubOrchestratorB), resultA); var resultC = await context.CallSubOrchestratorAsync<string>( nameof(SubOrchestratorC), resultC); return resultC; } }
62. @MarcDuiker 62 https://github.com/marcduiker/durable-functions-use-cases
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66. @MarcDuiker 66 Domain Bounded Context Bounded Context Bounded Context Bounded Context https://thedomaindrivendesign.io/bounded-context/
67. @MarcDuiker 67 Ecommerce Product Catalog Pricing Billing Shopping Basket https://thedomaindrivendesign.io/bounded-context/
68. @MarcDuiker 68 “Ubiquitous language identifies the terms and concepts within a bounded context that are unambiguous and agreed upon by all stakeholders.” https://thedomaindrivendesign.io/what-is-strategic-design
69. @MarcDuiker 69 Billing Shopping Basket https://thedomaindrivendesign.io/what-is-strategic-design
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73. @MarcDuiker 73 Bounded Context Bounded Context
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75. @MarcDuiker 75 “Resilience is the ability to provide and maintain an acceptable level of service in the face of faults and challenges to normal operation.” https://en.wikipedia.org/wiki/Resilience_(network)
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77. @MarcDuiker 77 https://learn.microsoft.com/en-us/azure/architecture/patterns/
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80. @MarcDuiker 80 Function App B Function App A Queue Storage
81. @MarcDuiker 81 public static class ChainingWithRetryExample { [FunctionName(nameof(ChainingWithRetryExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityWithRetryAsync<string>( nameof(ActivityFunctionA), new RetryOptions(TimeSpan.FromSeconds(5), 3) { BackoffCoefficient = 2 }, null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
82. @MarcDuiker 82 public static class ChainingWithRetryExample { [FunctionName(nameof(ChainingWithRetryExample))] public static async Task<string> RunOrchestrator( [OrchestrationTrigger] IDurableOrchestrationContext context) { var resultA = await context.CallActivityWithRetryAsync<string>( nameof(ActivityFunctionA), new RetryOptions(TimeSpan.FromSeconds(5), 3) { BackoffCoefficient = 2 }, null); var resultB = await context.CallActivityAsync<string>( nameof(ActivityFunctionB), resultA); var resultC = await context.CallActivityAsync<string>( nameof(ActivityFunctionC), resultB); return resultC; } }
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84. @MarcDuiker 84 Increase number of (virtual) machines Increase CPU / memory of one machine
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88. @MarcDuiker 88 scale out scale out
89. @MarcDuiker 89 scale out scale out https://learn.microsoft.com/en-us/azure/azure-functions/functions-scale#scale Use dedicated resource to its fullest
90. @MarcDuiker 90 scale out scale out https://learn.microsoft.com/en-us/azure/azure-functions/functions-scale#scale Use higher tier / sku Use regular tier / sku
91. @MarcDuiker 91 App Settings: FUNCTIONS_WORKER_PROCESS_COUNT Function App resource property: functionAppScaleLimit https://learn.microsoft.com/en-us/azure/azure-functions/event-driven-scaling https://learn.microsoft.com/en-us/azure/azure-functions/functions-best-practices SCALE_CONTROLLER_LOGGING_ENABLED
92. @MarcDuiker - Monitor your agility! - Ask yourself these questions before adding any code: - Do *I* need to write this? - Is this a good fit with the rest of the app? - What is the impact regarding resilience/scalability of the app?
93. @MarcDuiker linktr.ee/marcduiker