Improving legacy
2 likes840 views
The document discusses the importance of well-formed complex structures in software architecture to improve efficiency and save time through cognitive mechanisms like hierarchies and chunking. It emphasizes concepts such as modularity, high cohesion, and low coupling, alongside best practices like design patterns and test-driven development. Various tools and methodologies for analyzing and enhancing code quality and architecture are also presented.
Improving legacy
- 1. WPS - Workplace Solutions GmbH //// Hans-Henny-Jahnn-Weg 29 //// 22085 HAMBURG Improving Legacy Dr. Carola Lilienthal Carola.Lilienthal@wps.de, @cairolali www.wps.de
- 4. @cairolali
- 6. @cairolali 7 41 63 128 90 bis 15 Mio bis 5 Mio bis 1 Mio bis 500.000 bis 100.000
- 7. @cairolali HOW DO WE SPEND OUR TIME? 70% 20% 10% Code verstehen Problem lösen Code schreiben Code comprehension Problem solving Writing code
- 9. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata
- 10. @cairolali
- 13. @cairolali public class XYManager { void registerService(Service s)… Service getService(String n)... void initializeServiceRegistry()… void initializeEventQueue()… void sendEvent(Event event)… void initializePrinterQueue()… void printDocument(Doc d)…}
- 14. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity
- 15. @cairolali MODULARITY ▪High Cohesion and lose Coupling ▪Responsibility Driven Design ▪Separation of Concerns ▪Single Responsibility Principle
- 19. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity
- 22. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity Hierarchical Layerng
- 23. @cairolali
- 26. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity Hierarchical Layerng Pattern Consistency
- 27. @cairolali PATTERN HELP US TO BE QUICK Domain Module Model View Controller ValueObject Service BusinessObject
- 28. @cairolali WRONG PATTERN STOP THE FLOW Domain Module Model View Controller ValueObject Service BusinessObject Factory ✓ createBusinessObject() ✓ createValueObject() × calculate(BO) × process(BO)
- 29. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity Hierarchical Layerng Pattern Consistency
- 30. @cairolali
- 31. @cairolali TWO DIMENSIONS IN ON ARCHITECTURE Technical layering Domain layering Tree violations that are easy to resolve Difficult violations One component cuasing several problems One component causing a problem
- 32. @cairolali DOMAIN LAYERING IS MISSING Technical layering No domain layering Some violations of the technical layering Allmost all domain components need each other
- 33. @cairolali 119 classes from 4 components + 28 other classes
- 34. @cairolali 327 classes from 8 components That all need each other
- 36. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity Hierarchical Layerng Pattern Consistency
- 37. @cairolali MODULARITY: SIMULAR-SIZED Typical metrics: ▪ LOC per method, class, package, components ▪ Duplicated Code ▪ Cyclomatic complexity ▪ Is the system balanced at different levels? ▪ Which code sections stand out due to their size? Anti-Pattern „Godclass“
- 38. @cairolali UNEVEN MODULES One big monolith with satellites 950.860 LOC 84.808 LOC
- 39. @cairolali UNEVEN MODULES 9 Components = 17 Subsystems
- 40. @cairolali 128 BUILD UNITS WITH NUMBER OF CLASSES ▪ 3 Mio of 9 Mio LOC ▪ 1/3 of the system
- 41. @cairolali 5.270 CLASSES IN ONE CYCLE IN ONE BUILDUNIT
- 42. @cairolali DOMAIN-DRIVEN ARCHITECTURE Domain Module B Domain Module A Loose coupling = as little coupling as possible! Technicallayering Domain Module C User Interface User InterfaceUser Interface Domain Application Domain Application Domain Application
- 44. @cairolali DOMAIN MODULES? Models integrated in UseCasesUseCase-Driven
- 45. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Well-formed architecture Modularity Hierarchical Layering Pattern Consistency
- 47. @cairolali PATTERN CONFORMITY: GOOD EXAMPLE ☺ 90% of the source code can be assigned to pattern ☺ 0,1% violations between the pattern Eventer Processes Service
- 48. @cairolali
- 49. @cairolali WELL-FORMED COMPLEX STRUCTURES = SAVING TIME! Cognitive Mechanisms HierarchiesChunking Schemata Modularity Hierarchical Layerng Pattern Consistency → Consistent and integrated pattern → Use a pattern language → No cycles neither on architectural level nor on class level → responsibility → coupling → size → interfaces
- 50. @cairolali FREE TOOLS • SonarQube: ▪ Control station for quality metrics ▪ Platform for multiple plugins • JDepend: ▪ few metrics ▪ simple dependency analysis • JDepend + Google Architecture Rules: • simple architecture description • Ndepend/CDepend: ▪ Metrics ▪ dependency analysis • XRadar: ▪ Analysis of Java projects via maven ▪ Reports on complexity and architecture violations • Moose • Code City
- 51. @cairolali COMMERCIAL PRODUCTS ▪ Axivion Bauhaus: Java, C#, C/C++, Ada, VB and Cobol ▪ Lattix: Java, .Net, C/C++, Ada, Delphi and DB Systema ▪ Structure101: Java, C++, Ada ▪ SotoArc and Sonargraph: Java, C#, C/C++, ABAP, PHP ▪ Teamscale: C#, Java, ABAP ▪ Seerene: Java, C#, C/C++, ABAP
- 52. @cairolali ▪Do test driven development ▪Use design and architecture patterns ▪Write modular classes with one single responsibility ▪Aim for high cohesion and low coupling MOB ARCHITECTING WITH THE TEAM Structure101 SotoArc Lattix
- 53. @cairolali 612.869 LOC 14.756.435 LOC 252.062 LOC 804.093 LOC 543.388 LOC 1.035.668 LOC 486.358 LOC 175.258 LOC 42.311 LOC 193.383 LOC 643.466 LOC 245.754 LOC 2.890.204 LOC 141.696 LOC 512.086 LOC 9.988.363 LOC 200.591 LOC 922.949 LOC 22.658 LOC 663.862 LOC 3.270.188 LOC 1.521.357 LOC 0 2 4 6 8 10 MODULARITY MATURITY INDEX (MMI)
- 54. @cairolali @cairolali cl@wps.de Available in English since Summer 2019 www.sustainable-software-architecture.com THANK YOU FOR YOUR ATTENTION!