Unbreakable REST APIs: desenhando e implementando APIs robustas e previsíveis com fail fast e idempotency

(🎥 RECORDING: https://youtu.be/_MYy68tKsbA?list=PLHMMERsvy9EyWQPru4SrJAYHEGKfkjRgP&t=8954)

Existe uma grande diferença ao desenhar sistemas distribuídos e sistemas centralizados. Estar ciente delas é o que te permite construir sistemas escaláveis e resilientes.

Nesta talk você vai entender alguns desafios comuns e escorregadios ao construir sistemas distribuídos nesse mundo de microsserviços. Mas não se engane, até mesmo aquele seu CRUD simples com poucas chamadas a um banco de dados relacional pode ser uma fonte de incertezas e problemas de concorrência e consistência de dados.

Para lidar com estes percalços, você aprenderá como construir APIs REST robustas e previsíveis através de técnicas de resiliência como fail fast e idempotência. Apesar de ambas serem fáceis de entender, elas não necessariamente são simples de implementar. Para isso, tiraremos proveito do poder das transações e propriedades ACID dos bancos relacionais que nos ajudarão a minimizar vários desafios de concorrência e de cenários de indisponibilidade e inconsistência de dados.

Se você acha que uma API REST de CRUD é algo simples, então essa talk é para você!

Transcript

1. UNBREAKABLE REST APIs Desenhando e implementando APIs robustas e previsíveis com fail fast e idempotency Rafael Ponte | @rponte
6. CACHE
7. PROCESSAMENTO ASSINCRONO CACHE
8. BALANCEAMENTO DE CARGA CACHE PROCESSAMENTO ASSINCRONO
12. Se você não tem requisitos de desempenho ou throughput então você não tem problema de escala.
14. Microservices não existem para escalar aplicações, mas sim para escalar times.
15. https://www.youtube.com/watch?v=GBTdnfD6s5Q
16. https://www.youtube.com/watch?v=GBTdnfD6s5Q “ Eu não escrevi um livro sobre microservices, mas sim sobre como você arquiteta para Entrega Contínua. ” — Sam Newman
17. @duffleit Simple System
18. @duffleit Complicated System
19. @duffleit Complicated System
20. @duffleit Complicated System
21. @duffleit Complicated System 🔴
22. @duffleit Complicated System 🔴
23. Un·cer·tain·ty
24. O que é um Sistema Tolerante a Falhas?
25. https://deniseyu.io/art/
26. https://deniseyu.io/art/
27. https://deniseyu.io/art/
28. Desenhando sistemas distribuídos…
33. Spring Boot App
34. Spring Boot App
35. Spring Boot App Client Service
36. Spring Boot App Client Service
37. Spring Boot App Client Service Local Calls
38. Spring Boot App Client Service Local Calls
39. Spring Boot App Client Service Local Calls
40. Spring Boot App Client Service Local Calls Mas não aqui!
41. Spring Boot App Client Service Local Calls Mas não aqui!
42. Spring Boot App Client Service Local Calls
43. Em contrapartida…
44. Spring Boot App Spring Boot App
45. Spring Boot App Spring Boot App Client
46. Spring Boot App Spring Boot App Client Service
47. Spring Boot App Spring Boot App Client Service Internet
48. Spring Boot App Spring Boot App Client Service Internet
49. Spring Boot App Spring Boot App Client Service Internet Remote Calls
50. Spring Boot App Spring Boot App Client Service Internet Remote Calls
51. Spring Boot App Client Spring Boot App Service Internet Remote Calls
52. Spring Boot App Client Spring Boot App Service Internet Remote Calls
53. Spring Boot App Client Spring Boot App Service Internet Remote Calls
54. Spring Boot App Client Spring Boot App Service Internet Remote Calls
55. Spring Boot App Client Spring Boot App Service Internet Remote Calls
56. Spring Boot App Spring Boot App Internet Client Service Remote Calls
57. https://deniseyu.io/art/
58. https://deniseyu.io/art/
59. https://deniseyu.io/art/
60. https://deniseyu.io/art/
61. https://deniseyu.io/art/
63. Por que isso importa?
64. Spring Boot App Spring Boot App Spring Boot App Local Calls Remote Calls
65. Spring Boot App Spring Boot App Spring Boot App Centralized System Distributed System
66. Spring Boot App Spring Boot App Spring Boot App Centralized System Distributed System
67. — Martin Fowler First Law of Distributed Object Design: "don’t distribute your objects"
68. Mas se não tiver jeito…
69. Spring Boot App Client Spring Boot App Service Internet Distributed System
70. Spring Boot App Client Spring Boot App Service Internet Distributed System
76. Distributed System Spring Boot App Client Service Internet Database
77. Distributed System Spring Boot App Client Service Internet Database
78. Distributed System Spring Boot App Client Service Internet Database
79. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
80. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
81. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
82. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
83. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
84. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
85. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
86. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
87. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
88. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } } Injetado pelo Spring!
89. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
90. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
91. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
92. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
93. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
94. Design for Failures
95. @rponte Rafael Ponte Brazilian Software Engineer at aka Prince of the Ocean aka Maharaja of the Legacies 19+ years of experience working with Java and distributed systems Loves working with "boring techs"
96. Fortaleza - Terra do Sol
98. ?
99. ?
100. UNBREAKABLE REST APIs Desenhando e implementando APIs robustas e previsíveis com fail fast e idempotency Rafael Ponte | @rponte
101. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
102. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
103. O que acontece quando esperamos demais?
104. Client Service Network Database Spring Boot App
105. Client Service Network Database Spring Boot App
106. Client Service Network Database Spring Boot App
107. Client Service Network Database Spring Boot App
108. Client Service Network Database Spring Boot App
109. Client Service Network Database Spring Boot App
110. Client Service Network Database Spring Boot App
111. Client Service Network Database Spring Boot App
112. Client Service Network Database Spring Boot App
113. Client Service Network Database Spring Boot App
114. Client Service Network Database Spring Boot App
115. Client Service Network Database Spring Boot App
116. Client Service Network Database Spring Boot App
117. Client Service Network Database Spring Boot App
118. Client Service Network Database Spring Boot App
119. Client Service Network Database Spring Boot App
120. Client Service Network Database Spring Boot App
123. Tudo isso porque esperamos demais…
124. Fail Fast
125. Fail Fast with timeouts
126. Não con fi e no timeout default dos frameworks
127. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
128. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
129. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
130. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
131. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
132. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
133. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
134. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
135. @Repository public interface UserRepository extends JpaRepository<User, Long> { @QueryHints({ @QueryHint(name = "javax.persistence.query.timeout", value = "2000") }) @Override public Optional<User> findById(Long id); }
136. Quando a query demorar mais do que 2 seg…
137. SELECT u.* FROM user u WHERE u.id = 42 -- SQL Error: 0, SQLState: 57014 -- ERROR: canceling statement due to user request
138. Client Service Network Database Spring Boot App
139. Client Service Network Database Spring Boot App
140. Client Service Network Database Spring Boot App
141. Client Service Network Database Spring Boot App
142. Client Service Network Database Spring Boot App
143. Service Network Database Client Spring Boot App
144. O que acontece quando o cliente recebe um erro de timeout?
145. Un·cer·tain·ty
146. Client Service Network Database Spring Boot App
147. Client Service Network Database Spring Boot App
148. Client Service Network Database Spring Boot App
149. Client Service Network Database Spring Boot App
150. Client Service Network Database Spring Boot App
151. Client Service Network Database Spring Boot App
152. Client Service Network Database Spring Boot App
153. Client Service Network Database Spring Boot App
154. Como seu sistema se comporta quando o cliente re-tenta uma chamada?
155. @RestController public class FindUserController { @Autowired private UserRepository repository; @GetMapping("/api/users/{id}") public ResponseEntity<?> findById(@PathVariable Long id) { User user = repository.findById(id).orElseThrow(() -> { return new ResponseStatusException(NOT_FOUND, "User not found"); }); return ResponseEntity .ok(new UserResponse(user)); } }
156. Aplicação Usuário Banco de dados
157. Aplicação Usuário Banco de dados GET /api/users/42
158. Aplicação Usuário Banco de dados GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42
159. Aplicação Usuário Banco de dados GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42
160. Aplicação Usuário Banco de dados GET /api/users/42 SELECT u.* FROM user u WHERE ud.id = 42
161. Aplicação Usuário Banco de dados GET /api/users/42 HTTP 503 (SERVICE UNAVAILABLE) SELECT u.* FROM user u WHERE ud.id = 42
162. Aplicação Usuário Banco de dados GET /api/users/42 HTTP 503 (SERVICE UNAVAILABLE) SELECT u.* FROM user u WHERE ud.id = 42
163. Aplicação Usuário Banco de dados GET /api/users/42 HTTP 503 (SERVICE UNAVAILABLE) GET /api/users/42 SELECT u.* FROM user u WHERE ud.id = 42
164. Aplicação Usuário Banco de dados GET /api/users/42 HTTP 503 (SERVICE UNAVAILABLE) GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 SELECT u.* FROM user u WHERE ud.id = 42
165. Aplicação Usuário Banco de dados GET /api/users/42 HTTP 503 (SERVICE UNAVAILABLE) GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 SELECT u.* FROM user u WHERE ud.id = 42
166. Aplicação Usuário Banco de dados GET /api/users/42 HTTP 503 (SERVICE UNAVAILABLE) GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 HTTP 200 (OK) SELECT u.* FROM user u WHERE ud.id = 42
167. Mais do que isso…
168. Aplicação Usuário Banco de dados
169. Aplicação Usuário Banco de dados GET /api/users/42
170. Aplicação Usuário Banco de dados GET /api/users/42 SELECT u.* FROM user u WHERE ud.id = 42 5xx
171. Aplicação Usuário Banco de dados GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 5xx
172. Aplicação Usuário Banco de dados GET /api/users/42 GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 GET /api/users/42 5xx
173. Aplicação Usuário Banco de dados GET /api/users/42 GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 GET /api/users/42 GET /api/users/42 . . . 5xx
174. Aplicação Usuário Banco de dados GET /api/users/42 5xx GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 2xx SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 GET /api/users/42 GET /api/users/42 . . .
175. Aplicação Usuário Banco de dados GET /api/users/42 5xx GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 2xx SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 GET /api/users/42 GET /api/users/42 . . . Aplicação Usuário Banco de dados
176. Aplicação Usuário Banco de dados GET /api/users/42 5xx GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 2xx SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 GET /api/users/42 GET /api/users/42 . . . 2xx GET /api/users/42 Aplicação Usuário Banco de dados
177. Aplicação Usuário Banco de dados GET /api/users/42 5xx GET /api/users/42 SELECT 1 FROM user u WHERE ud.id = 42 2xx SELECT u.* FROM user u WHERE ud.id = 42 GET /api/users/42 GET /api/users/42 GET /api/users/42 GET /api/users/42 . . . ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com ... ... ... user Aplicação Usuário Banco de dados
178. IDEMPOTENCY
179. FUNCIONA MUITO BEM PARA ENDPOINTS DE LEITURA
180. FUNCIONA MUITO BEM PARA ENDPOINTS DE LEITURA …mas não tão bem para endpoints de escrita
181. IDEMPOTENCY O que acontece quando o cliente re-tenta uma requisição?
182. IDEMPOTENCY O que acontece quando o cliente re-tenta uma requisição? …de ESCRITA
183. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
184. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
185. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
186. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
187. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
188. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
189. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
190. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
191. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
192. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
193. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
194. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
195. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
196. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
197. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
198. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
199. Aplicação Usuário Banco de dados
200. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
201. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
202. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
203. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
204. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
205. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
206. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
207. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
208. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
209. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
210. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
211. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
212. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action);
213. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Aplicação Usuário Banco de dados
214. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx
215. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Aplicação Usuário Banco de dados Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Banco de dados
216. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Aplicação Usuário Banco de dados Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Banco de dados 👀
217. Aplicação Usuário Banco de dados INSERT INTO user (name , email) VALUES (:name, :email); POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } INSERT INTO user (name , email) VALUES (:name, :email); INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Network INSERT INTO user_audit (used_id, action) VALUES (:user_id, :action); Aplicação Usuário ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com 43 Gleice Elen gleice@gmail.com ... ... ... user 😱 Banco de dados
218. TEMOS UM DUPLICIDADE BUG
219. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
220. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
221. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } } Nosso endpoint NÃO é idempotente! 😰
222. https://opensource.zalando.com/restful-api-guidelines/#229 Zalando API Guidelines
223. https://opensource.zalando.com/restful-api-guidelines/#229 Idempotency Key Zalando API Guidelines
224. https://opensource.zalando.com/restful-api-guidelines/#229 Conditional Key Zalando API Guidelines
225. https://opensource.zalando.com/restful-api-guidelines/#229 Secondary Key Zalando API Guidelines
226. https://opensource.zalando.com/restful-api-guidelines/#229 Secondary Key Zalando API Guidelines
227. @Entity public class User { @Id @GeneratedValue private Long id; private String name; private String email; private LocalDateTime createdAt; // construtor, getters etc }
228. @Entity public class User { @Id @GeneratedValue private Long id; private String name; private String email; private LocalDateTime createdAt; // construtor, getters etc }
229. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { throw new ResponseStatusException(BAD_REQUEST, "User exists”); // http 400 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
230. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { throw new ResponseStatusException(BAD_REQUEST, "User exists”); // http 400 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
231. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { throw new ResponseStatusException(BAD_REQUEST, "User exists”); // http 400 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } } 🥳 Email como chave natural de idempotência!
232. SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email );
233. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { throw new ResponseStatusException(BAD_REQUEST, "User exists”); // http 400 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
234. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { throw new ResponseStatusException(BAD_REQUEST, "User exists”); // http 400 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } } 😵💫 Not cool!
235. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { throw new ResponseStatusException(BAD_REQUEST, "User exists”); // http 400 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
236. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
237. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } } 😍 Oh yeah!
238. Aplicação Usuário Banco de dados
239. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
240. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists…
241. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user…
242. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
243. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
244. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… Network
245. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… Network
246. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… Network POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
247. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… Network POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email );
248. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… Network POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email );
249. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); Network INSERT user_audit_… SELECT exists…
250. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); Network INSERT user_audit_… SELECT exists… Aplicação Usuário Banco de dados
251. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); Network INSERT user_audit_… SELECT exists… Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx
252. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); Network INSERT user_audit_… SELECT exists… Aplicação Usuário Banco de dados INSERT user… INSERT user_audit_… SELECT exists…
253. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); Network INSERT user_audit_… SELECT exists… Aplicação Usuário Banco de dados INSERT user… INSERT user_audit_… SELECT exists… SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); 💪
254. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); Network INSERT user_audit_… SELECT exists… Aplicação Usuário Banco de dados ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com ... ... ... user 🥳
255. E se…
256. Aplicação Usuário Banco de dados
257. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
258. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists…
259. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user…
260. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
261. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
262. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
263. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx
264. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
265. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email );
266. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email );
267. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx
268. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados
269. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx
270. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados SELECT exists… INSERT user… INSERT user_audit_…
271. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados SELECT exists… INSERT user… INSERT user_audit_… SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email );
272. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com ... ... ... user
273. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com ... ... ... user ID ACTION USER_ID ... ... ... ?? ?? ?? ... ... ... user_audit
274. Aplicação Usuário Banco de dados INSERT user… POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists ( SELECT 1 FROM user u WHERE u.email = :email ); INSERT user_audit_… SELECT exists… 5xx Aplicação Usuário Banco de dados ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com ... ... ... user ID ACTION USER_ID ... ... ... ?? ?? ?? ... ... ... user_audit 😱
275. TEMOS UM INCONSISTÊNCIA BUG
276. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
277. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
278. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); // inicia e comita uma transação UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); // inicia e comita uma transação return ResponseEntity .status(CREATED).build(); // http 201 } }
279. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); // inicia e comita uma transação UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); // inicia e comita uma transação return ResponseEntity .status(CREATED).build(); // http 201 } } Semelhante a auto_commit = true 😱
280. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
281. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
282. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
283. Para resolver…
284. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
286. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
287. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
288. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
289. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
290. Aplicação Usuário Banco de dados
291. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
292. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
293. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists…
294. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user…
295. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
296. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
297. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
298. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
299. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx
300. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
301. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
302. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
303. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
304. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_…
305. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx SELECT exists… INSERT user… INSERT user_audit_…
306. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 2xx Aplicação Usuário Banco de dados
307. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 2xx Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } 2xx
308. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 2xx Aplicação Usuário Banco de dados SELECT exists… INSERT user… INSERT user_audit_…
309. Aplicação Usuário Banco de dados POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 5xx POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } SELECT exists… INSERT user… INSERT user_audit_… 2xx Aplicação Usuário Banco de dados ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com ... ... ... user ID ACTION USER_ID ... ... ... 1024 created 42 ... ... ... user_audit 💪
310. E se…
311. Aplicação Usuário 1 Usuário 2
312. Aplicação Usuário 1 Usuário 2 POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
313. Aplicação Usuário 1 Usuário 2 POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
314. Aplicação Usuário 1 Usuário 2 POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
315. Aplicação Usuário 1 Usuário 2 HTTP 201 (CREATED) POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
316. Aplicação Usuário 1 Usuário 2 HTTP 201 (CREATED) HTTP 201 (CREATED) POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
317. SELECT u.* FROM user u
318. ID NAME EMAIL ... ... ... 42 Gleice Elen gleice@gmail.com 43 Gleice Elen gleice@gmail.com ... ... ... user 😱
319. TEMOS UM RACE CONDITION BUG
320. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
321. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
322. @RestController public class CreateNewUserController { private UserRepository repository; private UserAuditRepository auditRepository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { if (repository.existsByEmail(request.email())) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user); UserAudit audit = new UserAudit(user, "created"); auditRepository.save(audit); return ResponseEntity .status(CREATED).build(); // http 201 } }
323. boolean exists = repository.existsByEmail(request.email()); if (exists) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user);
324. boolean exists = repository.existsByEmail(request.email()); if (exists) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user);
325. boolean exists = repository.existsByEmail(request.email()); if (exists) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user);
326. boolean exists = repository.existsByEmail(request.email()); if (exists) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user);
327. boolean exists = repository.existsByEmail(request.email()); if (exists) { return ResponseEntity.ok("User exists”); // http 200 }; User user = request.toModel(); repository.save(user);
328. READ-MODIFY-WRITE
329. READ-MODIFY-WRITE
330. READ-MODIFY-WRITE
331. READ-MODIFY-WRITE
332. READ-MODIFY-WRITE ANTI-PATTERN
333. @Entity public class User { @Id @GeneratedValue private Long id; private String name; private String email; private LocalDateTime createdAt; // construtor, getters etc }
334. @Entity public class User { @Id @GeneratedValue private Long id; private String name; private String email; private LocalDateTime createdAt; // construtor, getters etc }
335. @Entity public class User { @Id @GeneratedValue private Long id; private String name; @Column(unique = true) private String email; private LocalDateTime createdAt; // construtor, getters etc }
336. ALTER TABLE user ADD CONSTRAINT uk_email UNIQUE (email);
337. Ou podemos aumentar o nível de isolamento da transação…
338. @Transactional( )
339. @Transactional( isolation = Isolation.SERIALIZABLE )
340. Aplicação Usuário 1 Usuário 2
341. Aplicação Usuário 1 Usuário 2 POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
342. Aplicação Usuário 1 Usuário 2 POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
343. Aplicação Usuário 1 Usuário 2 POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
344. Aplicação Usuário 1 Usuário 2 HTTP 201 (CREATED) POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
345. Aplicação Usuário 1 Usuário 2 HTTP 201 (CREATED) HTTP 409 (CONFLICT) POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” } POST /api/users { name: “Gleice Elen”, email: “gleice@gmail.com” }
347. Você percebeu?
348. Aplicação Usuário Banco de dados
349. Aplicação Usuário Banco de dados POST /api/users
350. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_…
351. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_…
352. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK
353. Aplicação Usuário Banco de dados POST /api/users 2xx OK SELECT exists… INSERT user… INSERT user_audit_…
354. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_…
355. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_…
356. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… ERROR
357. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… 5xx ERROR
358. TUDO NADA ou
359. TUDO ou NADA
360. TUDO NADA ou
361. Espera… onde já vimos isso? 🤔
362. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Aplicação Usuário Banco de dados
363. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Aplicação Usuário Banco de dados OK SELECT exists… INSERT user… INSERT user_audit_… Unit of Work
364. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Aplicação Usuário Banco de dados POST /api/users 2xx
365. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Aplicação Usuário Banco de dados 2xx POST /api/users Unit of Work
366. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Aplicação Usuário Banco de dados OK SELECT exists… INSERT user… INSERT user_audit_… 2xx POST /api/users Unit of Work Unit of Work
367. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Aplicação Usuário Banco de dados OK SELECT exists… INSERT user… INSERT user_audit_… 2xx POST /api/users Unit of Work Unit of Work
368. Aplicação Usuário Banco de dados POST /api/users SELECT exists… INSERT user… INSERT user_audit_… OK 2xx Usuário Banco de dados OK SELECT exists… INSERT user… INSERT user_audit_… POST /api/users 2xx Unit of Work
369. THE 1:1 MODEL Mapear uma transação para um HTTP request
370. THE 1:1 MODEL Brandur | @brandur Mapear uma transação para um HTTP request
371. https://brandur.org/http-transactions
372. @RestController public class CreateNewUserController { private UserRepository repository; @Transactional @PostMapping(“/api/users") public ResponseEntity<?> create(@Valid @RequestBody NewUserRequest request) { // lógica de negócio return ResponseEntity .status(OK).build(); // http 200 } }
373. CONCLUINDO
374. Sistemas distribuídos podem ser difíceis… 😬
376. “Use o banco apenas como repositório de dados.”
377. “Use o banco apenas como repositório de dados.” Não!
378. Recapitulando…
379. Agora temos uma API REST que…
381. …falha rapidamente
382. …permite re-tentativas do cliente …falha rapidamente
383. …abraça o tudo ou nada …permite re-tentativas do cliente …falha rapidamente
384. …abraça o tudo ou nada …permite re-tentativas do cliente …falha rapidamente …previne falhas de races conditions
386. Mas que serve para outras plataformas
387. @rponte Rafael Ponte Obrigado!!