Spring Cloud Sleuth 介绍及使用 · Spring Cloud 与 Docker 实战

这里我们以前面的`用户服务`添加[Sleuth](https://github.com/spring-cloud/spring-cloud-sleuth)为例。这里为了学习 Sleuth，因此只需要一个最简单的 Spring Boot 服务即可，先将实验二中的用户服务拷贝过来。 * 引入 Sleuth 依赖： ~~~xml <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-sleuth</artifactId> </dependency> ~~~ * 修改`application.yml`配置文件，增加如下内容： ~~~yml logging: level: root: INFO ...... org.springframework.cloud.sleuth: DEBUG ...... ~~~ 这里的配置也不是必选的，加上日志，只是为了看到更多 Sleuth 相关的日志。 * 测试运行启动用户服务过后，访问`http://localhost:8000/users/2`,可看到如下的日志内容： ~~~bash curl http://localhost:8000/users/2 ~~~ ~~~java Hibernate: select user0_.id as id1_0_0_, user0_.age as age2_0_0_, user0_.balance as balance3_0_0_, user0_.name as name4_0_0_, user0_.username as username5_0_0_ from user user0_ where user0_.id=? 2019-05-16 22:09:45.532 TRACE [microservice-provider-user,50227db7fe3a0e3d,50227db7fe3a0e3d,false] 84894 --- [nio-8000-exec-1] o.h.type.descriptor.sql.BasicBinder : binding parameter [1] as [BIGINT] - [2] 2019-05-16 22:09:45.547 TRACE [microservice-provider-user,50227db7fe3a0e3d,50227db7fe3a0e3d,false] 84894 --- [nio-8000-exec-1] o.h.type.descriptor.sql.BasicExtractor : extracted value ([age2_0_0_] : [INTEGER]) - [28] 2019-05-16 22:09:45.548 TRACE [microservice-provider-user,50227db7fe3a0e3d,50227db7fe3a0e3d,false] 84894 --- [nio-8000-exec-1] o.h.type.descriptor.sql.BasicExtractor : extracted value ([balance3_0_0_] : [NUMERIC]) - [180.00] 2019-05-16 22:09:45.548 TRACE [microservice-provider-user,50227db7fe3a0e3d,50227db7fe3a0e3d,false] 84894 --- [nio-8000-exec-1] o.h.type.descriptor.sql.BasicExtractor : extracted value ([name4_0_0_] : [VARCHAR]) - [李四] 2019-05-16 22:09:45.548 TRACE [microservice-provider-user,50227db7fe3a0e3d,50227db7fe3a0e3d,false] 84894 --- [nio-8000-exec-1] o.h.type.descriptor.sql.BasicExtractor : extracted value ([username5_0_0_] : [VARCHAR]) - [account2] ~~~ 仔细观察上面的日志中，多出来类似的信息： ~~~java [microservice-provider-user,50227db7fe3a0e3d,50227db7fe3a0e3d,false] ~~~ 是不是觉得看着这个毫无头绪，也看不出来个究竟。一个良好的监控，应该有一个人类亲和的界面，这个界面就是 Zipkin。那么，我们接下来就结合`Zipkin`来帮助我们吧～