Skip to content

Latest commit

 

History

History
153 lines (137 loc) · 5.26 KB

Practical Microservices-Packt Publishing(2017)-ReadingNotes.md

File metadata and controls

153 lines (137 loc) · 5.26 KB

Practical Microservices-Packt Publishing(2017)-ReadingNotes.md

微服务架构介绍

  • boot2docker依赖于VirtualBox？那么docker的图形化界面app呢？docker命令是否自动从hub上下载镜像？
  • Spring Boot：从maven pom.xml文件开始吗？starter项目可以自动生成的吧？

定义微服务组件

  • 发现服务：
    • Etcd by CoreOS
    • Eureka by Netflix
    • Consul by HashiCorp
    • Apache ZooKeeper
    • SkyDNS
    • SmartStack by Airbnb
  • Self-registration
  • 客户端发现：如Netflix Eureka，这违反了单一职责原则
    • vs 服务器端发现：LB网关
  • 外部化配置：NFS or AWS S3
    • Spring Boot属性查找顺序：*
      1. 命令行参数
      2. SPRING_APPLICATION_JSON环境变量
      3. JNDI java:comp/env
      4. System.getProperties()
      5. OS特定的环境变量
      6. RandomValuePropertySources ？
      7. application-{profile}.properties ？
      8. “Application properties inside/outside of your packaged JAR
      9. @PropertySource 支持从多个文件中加载？
      10. SpringApplication.setDefaultProperties
  • API网关 (缺点：...)
    • 认证
    • 不同协议的适配
    • LB
    • Response transform
    • Circuit breaker：Hystrix (by Netflix)，5秒内20个失败请求，fall back to dummy
    • 例子：Zuul
  • Sample应用：Credit risk engine
    • “Flyway is an open source database migration tool.”
     @SpringBootApplication
 public class UserServiceApplication { 
     @Value("${spring.datasource.url}") 
     private String url; 
     @Value("${spring.datasource.username}") 
     private String userName; 
     @Value("${spring.datasource.password}") 
     private String password;

     @Bean(initMethod = "migrate") 
 	public Flyway flyway() {
 		...

微服务节点间通信

  • Orchestration（有leader） versus choreography（分布式自治）
    • 第一种：The mediator service
  • 同步 vs 异步通信
    • 同步：断路器
     @RestController 
 @SpringBootApplication 
 @EnableCircuitBreaker 
 public class ConsumingApplication {
 	@Autowired 
 	private ConsumingService consumingService; 

 	@RequestMapping(method = RequestMethod.POST,value = "/book/{movieId}",produces = "application/json") 
 	public String book ticket(@PathVariable("userId") String userId, @PathVariable("movieId") String movieId){ 
 		return consumingService.bookAndRespond(userId,movieId); 
 	}
 	...
 }

 @Service 
 public class ConsumingService { 
  
  	@Autowired 
    	private  RestTemplate restTemplate; 
  
  	@HystrixCommand(fallbackMethod = "getAnotherCurentlyShowingMovie") 
   	public String bookAndRespond() { 
     	URI uri = URI.create("http://<application Ip:port>/bookingapplication/{userId}/{movieId}");
     		//？这里的userId、movieId参数是怎么注入的？？？示例代码有误？？？
  		return this.restTemplate.getForObject(uri, String.class); 
   	}
    • 异步
      • “message-based works on p2p communication, and event-based works based on publisher/subscriber.”
      • “Spring has inbuilt support for Kafka, RabbitMQ, and some other messaging brokers.”

安全

  • JWT（JSON Web Token）
  • OpenID
  • OAuth 2.0

创建有效的数据模型

  • The Saga pattern（可逆的消息流）
    • routing slip
     When an activity fails, it cleans up locally and then sends the routing slip backwards to the last completed activity's compensation address to unwind the transaction outcome.
    • initiator
    • Command Query Responsibility Segregation (CQRS)
  • Migrating a data model from monolithic to microservices
    • DDD
      • “For example, one user could have two or three addresses, so we need address management.”
    • Methods of data model migration
      • View
      • Clone table using trigger
      • Event sourcing（高级业务层log & replay）
       “The success of microservices architecture success lies in the secret of how good one can decompose bigger problems into smaller ones.”

测试

  • “Contract testing is different as compared to integration testing”（头一回听说‘合同测试’）
  • End-to-end testing mostly refers to testing the whole application, ...

部署

  • CI/CD：POM goals？
  • Linux系统上安装Docker（不像Mac／Windows那样，需要VirtualBox）
    • sudo apt-get install docker-engine
  • maven-docker plugin？
    • after pom.xml edit:
      • $ mvn package docker:build
    • FROM maven:3.3-jdk-8-onbuild

现存系统的演化

  • “The proper tools should be used for database migration; FlyBase and Liquibase are two such tools that will help you to upgrade your database automatically.”

监控和伸缩

  • Principles in scaling a microservices system
    • 'The Art of Scalability'里的scalecube：
      • X axis：scale out
      • Y：组件分解
      • Z：“a cross between x and y scaling strategies, using a data sharding based approach.” ？
  • Tools
    • QBit
    • ELK
    • Dynatrace
    • Sensu
    • AppDynamics
    • Instana
    • OpsClarity
    • 其他APM：“Prometheus, Netsil, Nagios, New Relic APM, Foglight, Compuware APM”
    • More：“etcd、Deis、Spotify Helios、Tutum、Project Atomic、Geard、Docker OpenStack、Coreos、Flynn、Tsuru”

故障排除

  • “Zipkin is an open source tool developer by Twitter to trace and debug into microservice. This is inspired by Google's Dapper Idea”