如何正确配置Kubernetes探测定时(用于Spring应用程序)

Question

我们有一个简单的Spring应用程序，它的启动时间不到30秒。因此，我将探测配置如下：

    readinessProbe:
      httpGet:
        path: /actuator/health/readiness
        port: 8080
      initialDelaySeconds: 30
      periodSeconds: 1
    livenessProbe:
      httpGet:
        path: /actuator/health/liveness
        port: 8080
      initialDelaySeconds: 30
      periodSeconds: 1

我的理解是，准备就绪探测器等待30秒，然后将成功(如果应用程序启动)。还有激活探测，延迟30秒(从部署开始)开始，并且几乎同时成功，就绪探测成功(如果应用程序已经准备好)。但我在日志中看到的是，准备好的探测器等待30秒，然后成功，但在那之后，又有30秒的等待时间，然后旧舱被关闭：

develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:07.378Z","logger":"org.springframework.boot.web.embedded.tomcat.TomcatWebServer","level":"INFO","thread":"main","message":"Tomcat started on port(s): 8080 (http) with context path ''"}
develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:07.387Z","logger":"org.springframework.data.repository.config.DeferredRepositoryInitializationListener","level":"INFO","thread":"main","message":"Triggering deferred initialization of Spring Data repositories…"}
develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:09.441Z","logger":"org.springframework.data.repository.config.DeferredRepositoryInitializationListener","level":"INFO","thread":"main","message":"Spring Data repositories initialized!"}
develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:09.469Z","logger":"com.example.Application","level":"INFO","thread":"main","message":"Started Application in 23.918 seconds (JVM running for 25.343)"}
develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:14.251Z","logger":"org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/]","level":"INFO","thread":"http-nio-8080-exec-1","message":"Initializing Spring DispatcherServlet 'dispatcherServlet'"}
develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:14.258Z","logger":"org.springframework.web.servlet.DispatcherServlet","level":"INFO","thread":"http-nio-8080-exec-1","message":"Initializing Servlet 'dispatcherServlet'"}
develop/demo-57c8984866-6v5sl[demo]: {"ts":"2020-10-08T17:33:14.292Z","logger":"org.springframework.web.servlet.DispatcherServlet","level":"INFO","thread":"http-nio-8080-exec-1","message":"Completed initialization in 30 ms"}
develop/demo-79cc9bc757-xlg6z[demo]: 2020-10-08T17:33:44.590172 Shutting down...
develop/demo-79cc9bc757-xlg6z[demo]: {"ts":"2020-10-08T17:33:44.658Z","logger":"org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean","level":"INFO","thread":"SpringContextShutdownHook","message":"Closing JPA EntityManagerFactory for persistence unit 'default'"}
develop/demo-79cc9bc757-xlg6z[demo]: {"ts":"2020-10-08T17:33:44.664Z","logger":"org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor","level":"INFO","thread":"SpringContextShutdownHook","message":"Shutting down ExecutorService 'applicationTaskExecutor'"}
develop/demo-79cc9bc757-xlg6z[demo]: {"ts":"2020-10-08T17:33:44.667Z","logger":"com.zaxxer.hikari.HikariDataSource","level":"INFO","thread":"SpringContextShutdownHook","message":"HikariPool-1 - Shutdown initiated..."}
develop/demo-79cc9bc757-xlg6z[demo]: {"ts":"2020-10-08T17:33:44.680Z","logger":"com.zaxxer.hikari.HikariDataSource","level":"INFO","thread":"SpringContextShutdownHook","message":"HikariPool-1 - Shutdown completed."}

第二个30秒等待时间的原因是什么(见第一个“关闭.”)？为了记录在案，不存在SIGTERM问题(应用程序正确地响应SIGTERM)。

更多信息

如果我对这些探测是如何工作的，请纠正我的错误:容器启动，此时准备就绪的初始延迟的计时器也启动。25秒后，应用程序就准备好了。再过5秒，就绪探测器开始击中应用程序/容器，它成功了，这样应用程序就准备好了(对吗？)在这一点上，我希望k8s发送到旧荚，要求关闭它的西格术语。但是，正如日志中所示，在新容器准备好之后，旧吊舱还在运行30秒。

也许，重新措辞这个问题会有帮助。我想在应用程序准备好后立即关闭旧吊舱。这款应用还不到30秒就准备好了。换句话说，我需要整个部署只需30秒(考虑到启动时间小于30秒，关机时间不到1秒)。为什么上面的配置不这样做呢？谢谢。

Answer 1

好的，我们用来管理库贝格清单的工具( k8s )和库对于minReadySeconds属性有一个不同的默认值(30秒)。我改变了这一切，一切都如期而至。

Answer 2

根据你的描述，你做的一切都很好。

我们观察到的是，与第一次记录启动信息的豆荚不同，另一个豆荚正在关闭。如果没有更多的信息，这看起来就像一个滚动的更新，等待关闭旧的豆荚，直到新的豆荚变得可用和健康。

您可以通过查看日志消息来判断:荚名位于每一行的前面。