Modern Software Architecture Styles and Patterns

1. MODERN SOFTWARE ARCHITECTURE styles and patterns

2. – Roy Fielding “an architectural style is a co-ordinated set of architectural constraints that restricts the roles/ features of architectural elements and the allowed relationships among those elements within any architecture that conforms to that style” R.T.Fielding “Architectural styles and the design of network-based software architectures. PhD thesis, University of California, 2000.

3. POSA - before and after

4. Layered Pipe-and-Filter Broker Client-Server Peer-to-Peer Blackboard

5. $ cat limerick.txt There was a young lady of Niger Who smiled as she rode on a tiger. They returned from the ride With the lady inside And a smile on the face of the tiger.

6. $ cat limerick.txt | tr -cs "[:alpha:]" "n" | awk '{print length(), $0}' | sort | uniq 1 a 2 as 2 of 2 on 3 And 3 Who 3 she 3 the 3 was 4 They 4 With 4 face 4 from 4 lady 4 ride 4 rode 5 Niger 5 There 5 smile 5 tiger 5 young 6 inside 6 smiled 8 returned

7. List<String> lines = Files.readAllLines(Paths.get("./limerick.txt"), Charset.defaultCharset()); Map<Integer, List<String>> wordGroups = lines.stream() .map(line -> line.replaceAll("W", "n").split("n")) .flatMap(Arrays::stream) .sorted() .distinct() .collect(Collectors.groupingBy(String::length)); wordGroups.forEach( (count, words) -> { words.forEach(word -> System.out.printf("%d %s %n", count, word)); }); 1 a 2 as 2 of 2 on 3 And 3 Who 3 she 3 the 3 was 4 They 4 With 4 face 4 from 4 lady 4 ride 4 rode 5 Niger 5 There 5 smile 5 tiger 5 young 6 inside 6 smiled 8 returned

8. What architectural style is this?

9. Real-world pipes-and-ﬁlters sediment pre- carbon ultra-ﬁlter post- carbon Filtered water

10. Pipe-and-filter: Benefits + Flexibility by filter exchange + Flexibility by recombination + Reuse of filter components + Rapid prototyping of pipelines Frank Buschmann, Regine Meunier, Hans Rohnert, Peter Sommerlad, and Michael Stal. 1996. Pattern-Oriented Software Architecture: A System of Patterns. John Wiley & Sons, Inc., NY, USA.

11. Pipe-and-filter: Liabilities - Sharing state information is expensive or inflexible - Efficiency gain by parallel processing is often an illusion - Data transformation overhead - Difficult to handle errors Frank Buschmann, Regine Meunier, Hans Rohnert, Peter Sommerlad, and Michael Stal. 1996. Pattern-Oriented Software Architecture: A System of Patterns. John Wiley & Sons, Inc., NY, USA.

12. What is the architecture style followed by World Wide Web (WWW)?

13. SOA (Service Oriented Architecture) Lambda Style Microservices REST (Representational State Transfer) Map-Reduce CQRS (Command-Query Responsibility Segregation ) Software Containers Event Sourcing

14. List<String> lines = Files.readAllLines(Paths.get("./limerick.txt"), Charset.defaultCharset()); Map<Integer, List<String>> wordGroups = lines.parallelStream() .map(line -> line.replaceAll("W", "n").split("n")) .flatMap(Arrays::stream) .sorted() .distinct() .collect(Collectors.groupingBy(String::length)); wordGroups.forEach( (count, words) -> { words.forEach(word -> System.out.printf("%d %s %n", count, word)); }); 1 a 2 as 2 of 2 on 3 And 3 Who 3 she 3 the 3 was 4 They 4 With 4 face 4 from 4 lady 4 ride 4 rode 5 Niger 5 There 5 smile 5 tiger 5 young 6 inside 6 smiled 8 returned

15. Java: Fork-join framework

16. Map-Reduce pattern Input Sara Booch Thayer Merlin Sara Ralph Merlin Tim Sara Christian Ralph Cormen … Computer Cluster map map map Sara, 1 Ralph, 1 Merlin, 1 Tim, 1 Sara, 1 Booch, 1 Thayer, 1 Merlin, 1 Sara, 1 Christian, 1 Ralph, 1 Cormen, 1 reduce reduce Sara, 3 Booch, 1 Thayer,1 Merlin, 2 Ralph, 2 Tim, 1 Christian, 1 Cormen, 1 … OutputSara, 1 Sara, 1 Sara, 1 Booch, 1 Thayer, 1 Merlin, 1 Merlin, 1 Ralph, 1 Ralph, 1 Tim, 1 Christian, 1 Cormen, 1

17. Lambda style Batch layer Serving layerSpeed layer

18. Lambda style source: https://spark-summit.org/2014/wp-content/uploads/2014/07/Lambda-Architecture-Jim-Scott..pdf

19. code-on- demand client-server cache statelesslayered system uniform interface REST constraints (in www)

20. Event Sourcing pattern source: https://msdn.microsoft.com/en-us/library/dn589792.aspx

21. Command Query Responsibility Segregation (CQRS) pattern source: https://msdn.microsoft.com/en-us/library/jj591573.da82141c6f9950d64c1263fa4da825ec(l=en-us).png

22. Microservices = “ﬁne grained SOA” or “SOA 2.0”

23. Microservices is an architectural style

24. Complex application = composed of tiny services

25. Communicate over REST API HTTPGET HTTPPUT HTTP POST HTTPDELETE

26. Underlying philosophy “do one thing and do it well”

27. Monolithic

28. Microservices

29. Conway’s law “Any organization that designs a system… will inevitably produce a design whose structure is a copy of the organization's communication structure”

30. Conway’s law Team 1 Team 2Team 3 Team 4

31. Conway’s law Team 1 Team 2 Team 3 Team 4

32. Monolithic to microservices

33. Monolithic to microservices

34. Service = manageable by “two pizza” team

35. Service = a team can DURS (Deploy, Update, Replace, Scale) Microservices = Damn U R Sexy

36. Amazon case study 2-tier architecture SOA Microservices

37. email sgganesh@gmail.com website www.designsmells.com twitter @GSamarthyam linkedin bit.ly/sgganesh slideshare slideshare.net/sgganesh

Modern Software Architecture Styles and Patterns

Ganesh Samarthyam

Modern Software Architecture Styles and Patterns