网站 术语,wordpress怎么开启下载收费功能,logo成品效果图网站,泰州住房城乡建设网站1.背景
之前写一篇文章Spring Boot集成disruptor快速入门demo#xff0c;有网友留言如下图#xff1a; 针对网友的留言#xff0c;那么我们如何解决这个问题呢
Spring-Boot应用停机时#xff0c;如何保证其内存消息都处理完成#xff1f;
2.解决方法 方法其实挺简单的有网友留言如下图 针对网友的留言那么我们如何解决这个问题呢
Spring-Boot应用停机时如何保证其内存消息都处理完成
2.解决方法
方法其实挺简单的disruptor有优雅停机方法不用我们自己去实现逻辑只需要调用 disruptor.shutdown() ;就可以实现优雅关闭。 1.禁用kill -9
使用kill -9命令强制终止进程在某些情况下可能会导致数据丢失或资源未正确释放。以下是一些原因和替代方案帮助你安全地停止应用程序
为什么避免使用kill -9 数据丢失kill -9会立即终止进程不会给应用程序任何机会去保存数据或完成正在进行的操作。 资源泄漏进程被强制终止后可能无法正确释放内存、文件句柄或网络连接等资源。 不执行清理逻辑应用程序通常在关闭时执行一些清理逻辑如关闭数据库连接、写入日志等kill -9会跳过这些步骤。
2.优雅停机方案
Spring Boot可以引入这个包
dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-actuator/artifactId
/dependency
放开shutdown接口
management:endpoints:web:exposure:include: *endpoint:shutdown:enabled: true
server:port: 8088然后post http://127.0.0.1:8088/actuator/shutdown 实现优雅停机但是spring boot 2.3以下停止后不能停止api继续对外。我们可以使用过滤器来禁止api对外提供服务手动设置HttpServletResponse.SC_SERVICE_UNAVAILABLE
package com.et.disruptor.config;import org.springframework.stereotype.Component;import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicBoolean;Component
public class GracefulShutdownFilter implements Filter {private final AtomicBoolean shuttingDown new AtomicBoolean(false);Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)throws IOException, ServletException {if (shuttingDown.get()) {((HttpServletResponse) response).setStatus(HttpServletResponse.SC_SERVICE_UNAVAILABLE);return;}chain.doFilter(request, response);}public void startShutdown() {shuttingDown.set(true);}
}
DisposableBean是Spring框架中的一个接口用于在Spring容器销毁Bean时执行一些自定义的清理逻辑。实现这个接口的Bean会在容器关闭时自动调用其destroy()方法。这对于需要在应用程序关闭时释放资源或执行其他清理操作的Bean非常有用。
package com.et.disruptor.config;import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;Component
public class GracefulShutdownManager implements DisposableBean {Autowiredprivate GracefulShutdownFilter shutdownFilter;AutowiredMqManager mqManager;Overridepublic void destroy() throws Exception {// reject new requestsshutdownFilter.startShutdown();//graceful shutdown DisruptormqManager.shutdownDisruptor(); // wait all events to complete// wait all your self-definite task finishwaitForTasksToComplete();}private void waitForTasksToComplete() throws InterruptedException {System.out.println(Waiting for tasks to complete...);// use CountDownLatch or other//mock task processThread.sleep(100000);}
}
3.disruptor优雅关闭
如果不想显示的调用shutdown 也可以用注解PreDestroy
package com.et.disruptor.config;import com.et.disruptor.event.HelloEventFactory;
import com.et.disruptor.event.HelloEventHandler;
import com.et.disruptor.model.MessageModel;
import com.lmax.disruptor.BlockingWaitStrategy;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.dsl.Disruptor;
import com.lmax.disruptor.dsl.ProducerType;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;Configuration
public class MqManager {private static DisruptorMessageModel disruptor;Bean(ringBuffer)public RingBufferMessageModel messageModelRingBuffer() {//define the thread pool for consumer message hander Disruptor touch the consumer event to process by java.util.concurrent.ExecutorSerivceExecutorService executor Executors.newFixedThreadPool(2);//define Event FactoryHelloEventFactory factory new HelloEventFactory();//ringbuffer byte sizeint bufferSize 1024 * 256;disruptor new Disruptor(factory, bufferSize, executor, ProducerType.SINGLE, new BlockingWaitStrategy());//set consumer eventdisruptor.handleEventsWith(new HelloEventHandler());//start disruptor threaddisruptor.start();//gain ringbuffer ringto product eventRingBufferMessageModel ringBuffer disruptor.getRingBuffer();return ringBuffer;}//PreDestroypublic void shutdownDisruptor() {if (disruptor ! null) {System.out.println(close Disruptor...);disruptor.shutdown(); //cl0se Disruptor}}
}
shudown方法源码
public void shutdown(long timeout, TimeUnit timeUnit) throws TimeoutException {long timeOutAt System.currentTimeMillis() timeUnit.toMillis(timeout);do {if (!this.hasBacklog()) {this.halt();return;}} while(timeout 0L || System.currentTimeMillis() timeOutAt);throw TimeoutException.INSTANCE;
}
这里会等到所有内存消息全部处理完
private boolean hasBacklog() {long cursor this.ringBuffer.getCursor();Sequence[] var3 this.consumerRepository.getLastSequenceInChain(false);int var4 var3.length;for(int var5 0; var5 var4; var5) {Sequence consumer var3[var5];if (cursor consumer.get()) {return true;}}return false;
}
以上只是一些关键代码所有代码请参见下面代码仓库
代码仓库
GitHub - Harries/springboot-demo: a simple springboot demo with some components for example: redis,solr,rockmq and so on.(Disruptor)
3.测试
启动Spring Boot应用post 请求http://127.0.0.1:8088/actuator/shutdown实现优雅停止访问http://127.0.0.1:8088/hello会报503错误后台会等待Disruptor处理内存消息后台等待处理其他的异步任务最后关闭Spring Boot应用
4.引用
https://medium.com/contact.technovisionconsulting/how-to-achieve-a-graceful-shutdown-in-spring-boot-ec93d55916edSpring Boot关闭时如何确保内存里面的mq消息被消费完 | Harries Blog™
