发现谁用 kill -9 关闭程序就开除！
鸭哥聊Java
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来源：blog.csdn.net/qq_33220089/article/details/105708331
kill -9 pid ？？？
kill可将指定的信息送至程序。预设的信息为SIGTERM(15)，可将指定程序终止。若仍无法终止该程序，可使用SIGKILL(9)信息尝试强制删除程序。程序或工作的编号可利用ps指令或jobs指令查看（这段话来自菜鸟教程）。
讲的这个复杂，简单点来说就是用来杀死linux中的进程，啥？你问我啥是进程？请自行百度。
我相信很多人都用过kill -9 pid 这个命令，彻底杀死进程的意思，一般情况我们使用它没有上面问题，但是在我们项目中使用它就有可能存在致命的问题。
kill -9 pid 带来的问题
由于kill -9 属于暴力删除，所以会给程序带来比较严重的后果，那究竟会带来什么后果呢？
举个栗子：转账功能，再给两个账户进行加钱扣钱的时候突然断电了？这个时候会发生什么事情？对于InnoDB存储引擎来说，没有什么损失，因为它支持事务，但是对于MyISAM引擎来说那简直就是灾难，为什么？假如给A账户扣了钱，现在需要将B账户加钱，这个时候停电了，就会造成，A的钱被扣了，但是B没有拿到这笔钱，这在生产环境是绝对不允许的，kill -9 相当于突然断电的效果。
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当然了，像转账这种，肯定不是使用MyISAM引擎，但是如今分布式火了起来，跨服务转账已经是很平常的事情，这种时候如果使用kill -9 去停止服务，那就不是你的事务能保证数据的准确性了，这个时候你可能会想到分布式事务，这个世界上没有绝对的安全系统或者架构，分布式事务也是一样，他也会存在问题，概率很小，如果一旦发生，损失有可能是无法弥补的，所以一定不能使用kill -9 去停止服务，因为你不知道他会造成什么后果。
在MyISAM引擎中表现的更明显，比如用户的信息由两张表维护，管理员修改用户信息的时候需要修改两张表，但由于你的kill -9 暴力结束项目，导致只修改成功了一张表，这也会导致数据的不一致性，这是小事，因为大不了再修改一次，但是金钱、合同这些重要的信息如果由于你的暴力删除导致错乱，我觉得可能比删库跑路还严重，至少删库还能恢复，你这个都不知道错在哪里。
那我们应该怎么结束项目呢？
其实java给我们提供了结束项目的功能，比如：tomcat可以使用shutdown.bat/shutdown.sh进行优雅结束。
什么叫优雅结束？
第一步：停止接收请求和内部线程。
第二步：判断是否有线程正在执行。
第三步：等待正在执行的线程执行完毕。
第四步：停止容器。
以上四步才是正常的结束流程，那springboot怎么正常结束服务呢？下面我介绍几种正常结束服务的方案，请拿好小本本做好笔记。
优雅结束服务
kill -15 pid
这种方式也会比较优雅的结束进程（项目），使用他的时候需要慎重，为什么呢？我们来看个例子
我写了一个普通的controller方法做测试
@GetMapping(value = "/test")public String test(){log.info("test --- start");try {Thread.sleep(100000);} catch (InterruptedException e) {e.printStackTrace();}log.info("test --- end");return "test";}
代码很简单，打印：test — start之后让让程序休眠100秒，然后再打印：test — end，在线程休眠中我们使用kill -15 pid来结束这个进程，你们猜 test — end会被打印吗？
application.yml
server:port: 9988
启动项目
sudo mvn spring-boot:run这是maven启动springboot项目的方式
sudo ps -ef |grep shutdownsudo curl 127.0.0.1:9988/testsudo kill -15 1408610:53:14.939 INFO 14086 --- [nio-9988-exec-1] com.ymy.controller.TestController : test --- start10:54:02.450 INFO 14086 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor': sleep interruptedat java.lang.Thread.sleep(Native Method)at com.ymy.controller.TestController.test(TestController.java:26)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:498)at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879)at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109)at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594)at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)at java.lang.Thread.run(Thread.java:748)10:54:04.574 INFO 14086 --- [nio-9988-exec-1] com.ymy.controller.TestController : test --- end10:54:04.610 ERROR 14086 --- [nio-9988-exec-1] o.s.web.servlet.HandlerExecutionChain : HandlerInterceptor.afterCompletion threw exception: nullat org.springframework.boot.actuate.metrics.web.servlet.LongTaskTimingHandlerInterceptor.stopLongTaskTimers(LongTaskTimingHandlerInterceptor.java:123) ~[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE]at org.springframework.boot.actuate.metrics.web.servlet.LongTaskTimingHandlerInterceptor.afterCompletion(LongTaskTimingHandlerInterceptor.java:79) ~[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE]at org.springframework.web.servlet.HandlerExecutionChain.triggerAfterCompletion(HandlerExecutionChain.java:179) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletion(DispatcherServlet.java:1427) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1060) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109) [spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) [tomcat-embed-core-9.0.33.jar:9.0.33]at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.33.jar:9.0.33]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_242]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_242]at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.33.jar:9.0.33]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_242]
package com.ymy.controller;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;import org.springframework.context.ConfigurableApplicationContext;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.bind.annotation.RestController;4jpublic class TestController implements ApplicationContextAware {private ApplicationContext context;public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {this.context = applicationContext;}(value = "/test")public String test(){log.info("test --- start");try {Thread.sleep(100000);} catch (InterruptedException e) {e.printStackTrace();}log.info("test --- end");return "test";}/*** 停机*/(value = "shutdown")public void shutdown(){ConfigurableApplicationContext cyx = (ConfigurableApplicationContext) context;cyx.close();}}
public void close() {synchronized(this.startupShutdownMonitor) {this.doClose();if (this.shutdownHook != null) {try {Runtime.getRuntime().removeShutdownHook(this.shutdownHook);} catch (IllegalStateException var4) {}}}}
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency>
server:port: 9988management:endpoints:web:exposure:include: shutdownendpoint:shutdown:enabled: trueserver:port: 8888
public String test(){System.out.println("test --- start");try {Thread.sleep(10000);} catch (InterruptedException e) {e.printStackTrace();}System.out.println("test --- end");return "hello";}
package com.ymy.config;import org.apache.catalina.connector.Connector;import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;import org.springframework.context.ApplicationListener;import org.springframework.context.event.ContextClosedEvent;import java.util.concurrent.Executor;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;public class ElegantShutdownConfig implements TomcatConnectorCustomizer, ApplicationListener<ContextClosedEvent> {private volatile Connector connector;private final int waitTime = 10;public void customize(Connector connector) {this.connector = connector;}public void onApplicationEvent(ContextClosedEvent event) {connector.pause();Executor executor = connector.getProtocolHandler().getExecutor();if (executor instanceof ThreadPoolExecutor) {try {ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) executor;threadPoolExecutor.shutdown();if (!threadPoolExecutor.awaitTermination(waitTime, TimeUnit.SECONDS)) {System.out.println("请尝试暴力关闭");}} catch (InterruptedException ex) {System.out.println("异常了");Thread.currentThread().interrupt();}}}}
package com.ymy;import com.ymy.config.ElegantShutdownConfig;import lombok.extern.slf4j.Slf4j;import org.apache.catalina.connector.Connector;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;import org.springframework.boot.web.servlet.server.ServletWebServerFactory;import org.springframework.context.ApplicationListener;import org.springframework.context.ConfigurableApplicationContext;import org.springframework.context.annotation.Bean;import org.springframework.context.event.ContextClosedEvent;import java.util.concurrent.Executor;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;@SpringBootApplicationpublic class ShutdownServerApplication {public static void main(String[] args) {ConfigurableApplicationContext run = SpringApplication.run(ShutdownServerApplication.class, args);run.registerShutdownHook();}@Beanpublic ElegantShutdownConfig elegantShutdownConfig() {return new ElegantShutdownConfig();}@Beanpublic ServletWebServerFactory servletContainer() {TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();tomcat.addConnectorCustomizers(elegantShutdownConfig());return tomcat;}}
package com.ymy.config;import org.springframework.context.annotation.Configuration;import javax.annotation.PreDestroy;@Configurationpublic class DataBackupConfig {@PreDestroypublic void backData(){System.out.println("正在备份数据。。。。。。。。。。。");}}