1 / 65

Natural Engineer – Next version

Natural Engineer – Refactoring: From Monolithic Applications to Service-Oriented Application Tom Philpott GSL Modernization@gensystems.com. Natural Engineer – Next version. Extract is around 60 times quicker Load is around 40% quicker

blair-bell
Download Presentation

Natural Engineer – Next version

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Natural Engineer – Refactoring:From Monolithic Applications to Service-Oriented ApplicationTom PhilpottGSLModernization@gensystems.com

  2. Natural Engineer – Next version • Extract is around 60 times quicker • Load is around 40% quicker • New GUI based on an object list rather than the function driven method of the current NEE.

  3. Application design through the ages • Structured Design • Object Oriented Programming • Service Oriented Architecture • Refactoring

  4. Structured Design • Coupling • Cohesion • Design Heuristics

  5. What influences Coupling? • Types of connection • Data • Control • Minimally connected • Normally connected • Pathological

  6. What influences Coupling? • Complexity of the interface • Basically, the number of arguments passed. • Information flow • Binding time

  7. Coupling • Common Environment coupling • Decoupling • Convert implicit references to explicit ones. • Localize common environments • Standardize connection

  8. Various takes on coupling

  9. Cohesion

  10. Various takes on cohesion

  11. Design Heuristics • A module shouldn’t be any bigger than 100 statements. • The span of control shouldn’t exceed 7 plus/minus 2. • A high span of control can meant the module was broken down too much. • When you identify reuse possibilities the process is called fan-in.

  12. Object Oriented Programming • Object • Class • Abstraction • Encapsulation • Inheritance • Polymorphism

  13. Object Oriented Design • Object structure modeling • Model business processes • Derive classes from these business processes • A business process is a set of activities for transforming some kind of input into a product that a customer is willing to pay for.

  14. Coad/Yourdon guidelines • Focus on clarity of design • If you cannot understand what someone is doing, you will not use the object. • Keep message protocols simple • Coupling is discussed here as well. If a message requires more than three parameters, it is badly designed. • Keep operations simple • Code should be less than one “page”. • Minimize design volatility • A bad design requiring frequent changes can be spotted through a configuration management system. • Minimize overall system size – big is bad. • A medium size system should not require more than a few dozen class hierarchies.

  15. Service Oriented Architecture • Utilizes loosely coupled software services to support business process requirements • Resources are available and accessible without any need to know the underlying platform • Not necessarily tied to a technology, could be RPC, DCOM, .Net, ORB or WSDL. • Architecture for creation of composite applications from loosely coupled services.

  16. SOA

  17. Refactoring Refactoring

  18. Refactoring Topics • What is Refactoring? • Small Scale Refactoring • The Full Scale Refactoring Methodology • Phase I: Preparation • Phase II: DB I/O Separation • Phase III: Presentation Layer Separation • Alternative thinking to Refactoring… • Analyze Data Model • Build Components per conceptual Entity

  19. What is Refactoring? • What is Refactoring ? • It can • Improve the design of the application • Systematically change program structures • Improve readability of code • Support agile program development • It does not • Change the program functionality Refactoring is a technique for restructuring or modifying existing source code without changing it’s external behavior.

  20. Natural Engineer: Refactoring • Aim of Refactoring Presentation dialog with I/O and some navigation logic Program with Presentation Logic Business Logic Database I/O Refactoring Business Logic Database I/O

  21. Natural Engineer: Refactoring • Accessing Refactoring

  22. Natural Engineer: Refactoring • The three phases of Refactoring

  23. Natural Engineer - Refactoring • Phase I – Preparation • Processes required in order to prepare the code for further refactoring • Phase II – DB Split • The ability to create subprograms that perform the DB access • Phase III – Presentation Split • The ability to create subprograms that contain the business logic

  24. Natural Engineer: Refactoring Natural Engineer Refactoring Phase I: Preparation

  25. Natural Engineer: Refactoring • Phase 1: Preparation

  26. Natural Engineer: Refactoring • Phase 1: Preparation

  27. Natural Engineer: Refactoring • Phase 1: Preparation

  28. Natural Engineer: Refactoring • Phase 1: Separate Processing Rules • Existing Code

  29. Natural Engineer: Refactoring • Phase 1: Separate Processing Rules

  30. Natural Engineer: Refactoring • Phase 1: Separate Processing Rules

  31. Natural Engineer: Refactoring • Phase I: Conversational DB Loops

  32. Natural Engineer: Refactoring • Phase 1: Conversational DB Loops

  33. Natural Engineer: Refactoring • Phase I: Similar Code Identification

  34. Natural Engineer: Refactoring • Phase I: Similar Code Identification

  35. Natural Engineer: Refactoring Natural Engineer Refactoring Phase II: Database I/O Separation

  36. Natural Engineer: Refactoring • Phase II – DB Split • Creates a subprogram per DDM/Key combination • Creates one subprogram per DDM for single ISN actions (DELETE, STORE, UPDATE, GET) • Creates one subprogram per application for BT and ET logic • Then replaces ADABAS logic in original program to CALLNAT to newly created subprograms. • Remember: USR4011N from SYSEXT to SYSTEM. This is the module that creates the hashing number for optimistic locking.

  37. Natural Engineer: Refactoring • Phase 2: Data I/O Separation

  38. Natural Engineer: Refactoring • Phase II – DB split – Original Code - READWH

  39. Natural Engineer: Refactoring • Phase II: DB Split • Examples of the PDAs created – Record and Key

  40. Natural Engineer: Refactoring • Phase II: DB Split • Subprogram accessing ADABAS – Decide Block

  41. Natural Engineer: Refactoring • Phase II – DB Split • Subroutine handling one particular access

  42. Natural Engineer: Refactoring • Phase II: DB Split • Replacement of ADABAS access in program

  43. Natural Engineer: Refactoring Natural Engineer Refactoring Phase III: Presentation Layer Separation

  44. Natural Engineer Refactoring • Phase III: Presentation Layer Split …processing…. SET KEY INPUT USING MAP…processing…. Dialog (Program) SET KEY INPUT USING MAP MOVE 1 TO #NAV-BLOCK CALLNAT ‘NEWSUBP’ #DATA Program Business logic (Subprogram) DECIDE ON FIRST VALUE OF #NAV-BLOCK VALUE 1 PERFORM ##BLOCK1 VALUE 2 PERFORM ##BLOCK2 .. END-DECIDE … DEFINE SUBROUTINE ##BLOCK1 Processing END-SUBROUTINE DEFINE SUBROUTINE ##BLOCK2 Processing END-SUBROUTINE

  45. Natural Engineer - Refactoring • Phase III – Presentation Layer Separation

  46. Natural Engineer - Refactoring • Phase III – Presentation Layer Separation

  47. Natural Engineer - Refactoring • Phase III – Presentation Layer Separation • Examination of Cross-Reference Records

  48. Natural Engineer: Refactoring • Phase III: Presentation Split • Items created: • GDAPDA-A – Copy of the GDA • XX021A01 – Map PDA • XX021A02 – Local data PDA • XX021A03 – PDA of XX021L01 • XX021A04 – PDA of XX021L02 • XX021A05 – PDA of XXMTHVAL • XX021C01/2 – Copy data Map/Local • XX021N01 – Subprogram with BL • XX021P01 – Dialogue program

  49. Natural Engineer Refactoring • Phase III – Presentation Layer Separation

  50. Natural Engineer Refactoring • Phase III – Presentation Layer Separation

More Related