Software Architecture Anti-patterns

Talk given at Dutch PHP Conference 2016, with my co-host Dimitrios Psarrou.

Have you ever noticed that the project with too many architects trying to add their own favourite pattern changes into super complicated mess? And the project with an architect that sees all technological options equally viable never ever starts?

All those situations have been categorised, named and shamed and we will present them to you on a gold plated tray.

Transcript

1. SOFTWARE ARCHITECTURE ANTI-PATTERNS Image source: https://www.flickr.com/photos/britfatcat/9066456506/
2. JAKUB GADKOWSKI JAKUB@ENDOUBLE.COM @JAKUBGA DIMITRIOS PSARROU DIMITRIOS@ENDOUBLE.COM ABOUT US
3. A SHORT INTRODUCTION
4. A SHORT INTRODUCTION PATTERN Describes a problem encountered on a regular basis, followed by abstracted solution. ANTI PATTERN Describes a broken solution and then proposes refactored, fixed solution.
5. WHY ANTI-PATTERNS? ‣ Way to communicate. ‣ Avoid broken solutions.
6. TYPES OF ANTI-PATTERNS ‣ Development anti-patterns ‣ Architectural anti-patterns ‣ Managerial anti-patterns
7. BIG BALL OF MUD
8. Image source: https://smilekiddo.wordpress.com/2011/05/13/chore-supports/
9. BIG BALL OF MUD ANTI-PATTERN TYPICAL SYMPTOMS AND CAUSES ‣ Bad management decisions. ‣ Change of requirements. ‣ Inexperienced developers.
10. ‣ Small step refactoring. ‣ Just tear it down. BIG BALL OF MUD ANTI-PATTERN SOLUTION Image source: http://gizmodo.com/10-mesmerizing-gifs-of-giant-buildings-being-demolished-611490671
11. STOVEPIPE ARCHITECTURE
12. Image source: https://www.flickr.com/photos/egarc2/2432270195/
13. STOVEPIPE ANTI-PATTERN TYPICAL SYMPTOMS AND CAUSES ‣ Lack of an system strategy. ‣ Lack of communication. ‣ Lack of abstraction.
14. STOVEPIPE ANTI-PATTERN SOLUTION ‣ Coordination between systems. ‣ Architecture management. ‣ Composition and delegation.
15. THE NEW TOYS
17. THE NEW TOYS ANTI-PATTERN SYMPTOMS AND CAUSES ‣ Introducing new technology because it’s new. ‣ Picking technology that looks good on CV. ‣ Putting technology before user’s needs.
18. THE NEW TOYS ANTI-PATTERN SOLUTION ‣ Does it solve end user problems? ‣ Does it make the system more complex? ‣ Is it proven technology for this solution? ‣ Is it compatible with the team skill set?
19. GOLD PLATING
20. src: https://pbs.twimg.com/media/CPiJMG2WwAAdwAe.png
21. GOLD PLATING ➤ The additional effort does not add value ➤ Also found in management • PMBoK • Prince 2 ➤ Introduces new risks • testing • documentation • costs • timelines src: http://www.stellman-greene.com/blog/wp-content/uploads/2007/06/silverware.png
22. GOLD PLATING - PREMATURE OPTIMIZATION src: http://www.cihataltuntas.com/wp-content/PrematureOptimization_D748/premature6.jpg
23. GOLD PLATING - PREMATURE/ACCIDENTAL COMPLEXITY src: http://s2.quickmeme.com/img/aa/aab05dd5de57f6aa638348aa48cd80d5b522f8c70a35d58044c03b56dfdc5391.jpg
24. GOLD PLATING - SOLUTION src: https://imgflip.com/memegenerator/61458110/Not-Today
25. THE GRAND OLD DUKE OF YORK https://s-media-cache-ak0.pinimg.com/236x/62/41/fc/6241fc95fd6b999fe0aa2d3606d682db.jpg
26. THE GRAND OLD DUKE OF YORK Abstractionists versus Implementationists src: http://www.cliffedgemarketing.com/assets/img/blog/Thinker%20vs.%20doer%20final.jpg
27. THE GRAND OLD DUKE OF YORK - CAUSES AND CONSEQUENCES Software usability and system maintenance are impacted Excessive complexity Abstractions are compromised Abstractionists are outvoted Software design disasters that make the system difficult to develop could have been prevented by using effective abstraction principles
28. THE GRAND OLD DUKE OF YORK Specialisations: ➤ Architects ➤ Component Developers ➤ Application Developers
29. THE ARMCHAIR ARCHITECT
30. THE ARMCHAIR ARCHITECT ➤ Can solve all the software world's problems from his armchair ➤ Implementation is out of scope ➤ Avoids testing his great ideas with reality ➤ Dismisses everything that anyone else has done Popular quotes ➤ User interfaces are all worthless ➤ All web browsers, including the Web itself, are worthless ➤ Everything will change within 5-10 years, due to me personally ➤ Programmers are all unethical idiots working for evil corporations
31. [Insert photo of Jay and Dimi here]
32. THE ARMCHAIR ARCHITECT Causes ➤ Whiteboard sketches are handed off as final architecture ➤ Architects don’t code ➤ Architects play golf ➤ Blame the implementers src: https://allthingslearning.files.wordpress.com/2012/06/ivory-tower-tg-version.png
33. THE ARMCHAIR ARCHITECT - SOLUTION ➤ Be involved with the project ➤ Eat your own dog food ➤ Lead by example ➤ Pair programming ➤ Code reviewing ➤ Shared understanding src: http://www.informit.com/content/images/chap3_9780321247131/elementLinks/03fig01.jpg
34. COVER YOUR ASSETS
35. Covering your assets - providing excessive amount of documents and options without actually making any decision. Image source: Fallout 4, copyright Bethesda 2016
36. COVER YOUR ASSETS ANTI-PATTERN TYPICAL SYMPTOMS AND CAUSES ‣ Document Driven Development syndrome. ‣ Safeguarding from (all) potential failures.
37. COVER YOUR ASSETS ANTI-PATTERN SOLUTION ‣ Propose options, explain and recommend the best solution. ‣ Introduce Architecture Blueprints.
38. COVER YOUR ASSETS ANTI-PATTERN SOLUTION
39. DESIGN BY COMMITTEE
41. DESIGN BY COMMITTEE ANTI-PATTERN TYPICAL SYMPTOMS AND CAUSES ‣ Conflicting interpretations of the design. ‣ Politics affects the design. ‣ Unproductive, slow process of meetings and improvements.
42. DESIGN BY COMMITTEE ANTI-PATTERN SOLUTION ‣ Small teams of experts. ‣ Establish roles and responsibilities. ‣ Improve committee meetings. ‣ Improve decision process: ATAM, LAAAM.
43. REINVENT THE WHEEL
44. Image source: “MythBusters”, episode “Square Wheels”, 2012 Discovery
45. REINVENT THE WHEEL ANTI-PATTERN TYPICAL SYMPTOMS AND CAUSES ‣ Closed system architecture. ‣ Lack of knowledge. ‣ Jealousy. ‣ Detrimental enterprise culture.
46. REINVENT THE WHEEL ANTI-PATTERN SOLUTION ‣ Improve (internal) communication. ‣ Research on existing solutions. ‣ Influence company culture.
47. VENDOR LOCK-IN
48. src: https://imgflip.com/memegenerator/Overly-Attached-Girlfriend
49. VENDOR LOCK-IN Aka Bondage and Submission ➤ Complete dependency on vendor implementation ➤ Lack of control ➤ Quantifiable ➤ Exceptions • When the majority of functionality needed is made by a specific vendor
50. VENDOR LOCK-IN Vendor lock in is everywhere ➤ Business lock in ➤ Technology lock in ➤ Cloud lock in src: http://www.mspmentor.net/wp-content/uploads/2012/11/cloud-lock-in-300x225.jpeg
51. VENDOR LOCK-IN - SOLUTION: ISOLATION LAYER src: http://antipatterns.com/vendorlockin.htm
52. VENDOR LOCK-IN - TAKEAWAYS ➤ Vendor lock in is quantifiable ➤ Business lock in is the hardest to escape ➤ There is no real elimination of lock in. Only mitigation of the costs ➤ Pay the switching costs when the lock in becomes an impediment to your objectives ➤ Always prepare your exit strategy
53. SPIDERWEB ARCHITECTURE Spider webs are beautiful..
54. YOUR WEB SERVICES ARE NOT src: http://techblog.netflix.com/2013_01_01_archive.html
55. SPIDERWEB ARCHITECTURE ➤ Aka a million services all in a row ➤ Creating large number of services, because you can. ➤ Problems • Confusion • Maintenance cost ‣ Solution • Let the requirements drive what needs to be exposed
56. POINT TO POINT WEB SERVICES
57. src: https://zato.io/docs/intro/esb-soa.html
58. src: https://zato.io/docs/intro/esb-soa.html
59. POINT TO POINT SERVICES - SOLUTION ➤ Gateways ➤ Brokering
60. ONE MODEL TO RULE THEM ALL
61. src: https://imgflip.com/memegenerator/28416787/the-one-ring
62. ONE MODEL TO RULE THEM ALL ➤ Single domain fallacy ➤ There are no bounded contexts ➤ Complexity and integration issues
63. ONE MODEL TO RULE THEM ALL - SOLUTION ➤ DDD ➤ Bounded contexts ➤ CQRS src: http://martinfowler.com/bliki/CQRS.html
64. THANK YOU! PLEASE RATE US: HTTPS://JOIND.IN/TALK/5884E
65. QUESTIONS? We will answer any question as long as you can solve this within 30secs
66. REFERENCES ➤ Antipatterns, Refactoring Software, Architectures, Projects in Crisis, William J. Brown Raphael C. Malveau Hays W. McCormick III Thomas J. Mowbray John Wiley & Sons, Inc. 1998 ➤ Adrian Cockcroft - OpenStack Silicon Valley 2015 - Web Services and Microservices: The Effect on Vendor Lock In ➤ Domain Driven Design - Eric Evans, 2004 ➤ Implementing DDD - Vaugh Vernon 2013 ➤ Building Microservices - Sam Newman 2015 ➤ Daniel Bryant - The seven deadly sins of micro services - Devox UK, 2016 ➤ https://sourcemaking.com/antipatterns ➤ http://c2.com/cgi/wiki ➤ http://nealford.com/ ➤ http://martinfowler.com/ ➤ https://www.nginx.com/blog/building-microservices-inter-process-communication/ ➤ https://www.infoq.com/articles/SOA-anti-patterns ➤ http://richard.dallaway.com/architecture/