Midwest PHP 2020 - Web Scale System Design and Architecture

Let's walk through different system designs and architecture decisions for building a large scale PHP application.

We'll cover SOLID, Application Architectures, Platform Architectures, and walk through an example of scaling a system.

Transcript

1. web scale & System Design Architecture
2. Who is this guy? Ben Edmunds Open Source Author PHP Town Hall Podcast Staff Eng @ Wayfair
3. Design Principles
8. Design Principles Single Responsibility Principle (SRP)
9. Design Principles
10. Design Principles "what I mean by 'focusing one's attention upon some aspect': it does not mean ignoring the other aspects, it is just doing justice to the fact that from this aspect's point of view, the other is irrelevant. It is being one- and multiple-track minded simultaneously." - Edsger W. Dijkstra
11. SRP interface User { public function getEmail(); public function savePost(); }
12. SRP interface User { public function getEmail(); } interface Post { public function setUserId(); public function save(); }
13. SRP interface Order { public function getTotal(); public function getProducts(); public function getPdf(); }
14. SRP interface Order { public function getTotal(); public function getProducts(); } interface OrderPdfReport { public function setOrder(Order $order); public function getPdf(); }
16. Design Principles Open-Closed Principle (OCP)
17. Design Principles
18. Design Principles OPEN
 "A module will be said to be open if it is still available for extension. For example, it should be possible to add fields to the data structures it contains, or new elements to the set of functions it performs." CLOSED
 "A module will be said to be closed if [it] is available for use by other modules. This assumes that the module has been given a well-defined, stable description (the interface in the sense of information hiding)" - Bertrand Meyer
19. OCP class OrderPdfGeneratorJob { public function generatePdf(); } class OrderGeoLocatorJob { public function locate(); }
20. OCP class ProcessWorker { public function process($job) { if ($job instanceof OrderPdfGeneratorJob) { $job->generatePdf(); } elseif ($job instanceof OrderGeoLocatorJob) { $job->locate(); }
21. OCP interface Job { public function process(); } class OrderPdfGenerator implements Job { public function process(); } class OrderGeoLocator implements Job { public function process();
22. OCP class ProcessWorker { public function process(Job $job) { return $job->process(); } }
24. Design Principles Liskov Substitution Principle (LSP)
25. Design Principles
26. Design Principles 
 "Let Φ(x) be a property provable about objects x of type T. Then Φ(y) should be true for objects y of type S where S is a subtype of T." - Barbara Liskov
27. LSP interface Duck { public void walk(); public void quack(); } class Mallard implements Duck
28. LSP interface Duck { public void walk(); public void quack(); } class RubberDuck implements Duck
29. LSP interface WaterToy { public void isFun(); public void floats(); } class RubberDuck implements WaterToy
31. Design Principles Interface Segregation Principle (ISP)
32. Design Principles
33. Design Principles 
 "Classes that have “fat” interfaces are classes whose interfaces are not cohesive." - Robert C. Martin
34. ISP interface Job { public function process(); } class OrderPdfGenerator implements Job { public function process(); } class OrderGeoLocator implements Job { public function process();
35. ISP interface Job { public function process(); public function getLatLong(); } class OrderPdfGenerator implements Job { public function save(); uhOhhhh() }
36. ISP interface Job { public function process(); } interface Geo { public function getLatLng(); } class OrderGeoLocator implements Job, Geo { public function process(); public function getLatLng(); }
38. Design Principles Dependency Inversion Principle (DIP)
39. Design Principles
40. Design Principles 
 "Code to the interface" - Me & others
41. DIP class SuperUser {} $user = new SuperUser; class Post { function setUser(SuperUser $user); }
42. DIP interface User {} class SuperUser implements User {} $user = new SuperUser; class Post { function setUser(User $user); }
43. DIP interface User {} class SuperUser implements User {} class RegularUser implements User {} $user = new RegularUser; class Post { function setUser(User $user); }
45. Architecture Patterns
47. Application Architectures
49. App Architectures Layered / N-Tiered
50. App Architectures Presentation Logic Data HTML / CSS Javascript Templating PHP APIs Glue Postgres Redis Config
51. App Architectures Presentation Logic Data Authentication Product Cart
52. App Architectures HTML / CSS PHP DB CLIENT
53. App Architectures CLIENT Presentation Cart
54. App Architectures Presentation Logic Data Authentication Product Cart
55. Platform Architectures Microkernel
56. App Architectures CORE Plugin Component Extension i n t e r f a c e
57. App Architectures DB Postgres MySQL SQL Server P D O
58. Platform Architectures
59. Platform Architectures Microservices Monolith SOA
61. Platform Architectures Microservices SOA Monolith
62. Platform Architectures Monolith
63. Platform Architectures "Almost all the successful microservice stories have started with a monolith that got too big and was broken up" 
 - Martin Fowler
64. Platform Architectures Coupling
65. Platform Architectures Development Speed
66. Platform Architectures Maintenance
67. Platform Architectures Monorepo Myth
68. Platform Architectures Trunk Based
69. Platform Architectures Scaling
70. Platform Architectures Microservices Monolith SOA
71. Platform Architectures Coupling
72. Platform Architectures Team Ownership
73. Platform Architectures APIs as First Class Citizens
74. Platform Architectures Scaling
75. Platform Architectures Routing
76. Platform Architectures Many Monoliths
77. Platform Architectures Repo Management
78. Platform Architectures Monolith SOA Microservices
79. Platform Architectures Coupling
80. Platform Architectures Deployments
81. Platform Architectures Scaling
82. Platform Architectures More Services = More Problems - Notorious B.I.G.
83. Platform Architectures Microservices Monolith SOA
84. Data Architectures
85. Data Architectures https://github.com/UWCoffeeNCode/resources/wiki/SQL-and-NoSQL-Databases
86. Data Architectures Relational / SQL
87. Data Architectures NoSQL
88. Data Architectures Time Series DBs
89. Data Architectures Combos
90. Data Architectures Scaling
92. Example Design
93. Pastebin Example
94. Pastebin Requirements • Save with unique URL • Retrieve code via URL • Don't break
95. Pastebin Scale • Writes / second • Reads / second • Storage
96. Pastebin Scale • Writes / second • Reads / second • Storage 1 x 86400 50 x 86400 86400x10kb = 864MB/day
97. Pastebin Scale (864MB/day x 30) x 6 = 155 GB x 1.25 = 193GB
98. Pastebin Scale (864MB/day x 30) x 6 = 155 GB x 1.25 = 193GB 200GB for 6 months
99. Pastebin API • GET /$primaryKey • POST /
100. Pastebin Database • id: serial • content: text • created_at: datetime
101. Pastebin CLIENT API DB
102. Pastebin ⚠ Scenario ⚠ • IDs becoming too long • Don't want users guessing other's URLs
103. Pastebin Hashing 86400 per day 86400 x (365 x 10) 316 million hashes
104. Pastebin Hashing base64 encoding 64^5 >1 billion
105. Pastebin Database • hash: varchar(5) • content: text • created_at: datetime
106. Pastebin API • POST /
 -> generateHash()
 -> checkHash()
 -> save()

107. Pastebin API • POST /
 -> getHash()
 -> save()

108. Pastebin CLIENT API Key Serv DB
109. Pastebin ⚠ Scenario ⚠ • Large pastes could fill up 
 the DB
110. Pastebin Database • hash: varchar(5) • created_at: datetime
111. Pastebin Database • hash: varchar(5) • created_at: datetime Object Storage • {$hash}
112. Pastebin CLIENT API Obj DB Key Serv
113. Pastebin API • POST /
 -> getHash()
 -> saveDb((){
 saveObj()
 })

114. Pastebin CLIENT API Obj Cache DB Key Serv
115. Pastebin ⚠ Next Steps ⚠ • More Caching • Load Balancing • Separate reads / writes • Reporting System
116. Pastebin CLIENT Obj Cache Service Service DB Key Serv
117. Pastebin CLIENT API Obj Cache R e q u e s t DB Key Serv
118. Pastebin CLIENT API Obj R e q u e s t API DB DB DB Key Serv
119. Pastebin CLIENT API Obj R e q u e s t API DB DB DB Key Serv Iteration =
120. Q/A
121. Resources
122. Resources
123. Resources
124. Resources
125. Thank You @benedmunds ben.edmunds@gmail.com