SpringBoot 优雅停机实现原理与最佳实践指南

ERROR ... - Error creating bean with name 'orderController': 
Singleton bean creation not allowed while singletons of this factory are in destruction
org.springframework.beans.factory.BeanCreationNotAllowedException: ...

JVM
 └── 内嵌 Web 容器（如 Tomcat）
      └── Servlet 容器（StandardContext）
           └── DispatcherServlet（Spring MVC 入口）
                └── Spring ApplicationContext（IoC 容器）
                     └── 所有 Spring Bean（@Controller, @Service 等）

@Component
public class GracefulShutdown implements TomcatConnectorCustomizer, 
                                      ApplicationListener<ContextClosedEvent> {
    private volatile Connector connector;
    @Override
    public void customize(Connector connector) {
        this.connector = connector;
    }
    @Override
    public void onApplicationEvent(ContextClosedEvent event) {
        connector.pause(); // 停止接收新请求
        Executor executor = connector.getProtocolHandler().getExecutor();
        if (executor instanceof ThreadPoolExecutor) {
            try {
                ((ThreadPoolExecutor) executor).shutdown();
                ((ThreadPoolExecutor) executor).awaitTermination(30, TimeUnit.SECONDS);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
    }
}

@Bean
public ServletWebServerFactory servletContainer() {
    TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
    tomcat.addConnectorCustomizers(gracefulShutdown());
    return tomcat;
}

server:
  shutdown: graceful          # 启用优雅停机
spring:
  lifecycle:
    timeout-per-shutdown-phase: 30s  # 等待超时时间

@Override
public int getPhase() {
    return Integer.MAX_VALUE; // 最后启动，最先停止
}

server:
  shutdown: graceful
spring:
  lifecycle:
    timeout-per-shutdown-phase: 45s  # > 业务最大请求耗时

spec:
  containers:
    - name: app
      lifecycle:
        preStop:
          exec:
            command: ["sleep", "15"]  # 给 LB 时间摘除节点
      terminationGracePeriodSeconds: 60

management:
  endpoint:
    shutdown:
      enabled: true
  endpoints:
    web:
      exposure:
        include: "shutdown"

curl -X POST http://localhost:8080/actuator/shutdown