Springboot吞吐量优化解决方案

雨点打透心脏的1/2处 2022-03-15 04:54 203阅读 0赞

一、异步执行  
实现方式二种：  
1.使用异步注解`@aysnc`、`启动类：添加@EnableAsync注解`  
2.JDK 8本身有一个非常好用的Future类——`CompletableFuture`

@AllArgsConstructor
    public class AskThread implements Runnable{
        private CompletableFuture<Integer> re = null;
    
        public void run() {
            int myRe = 0;
            try {
                myRe = re.get() * re.get();
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println(myRe);
        }
    
        public static void main(String[] args) throws InterruptedException {
            final CompletableFuture<Integer> future = new CompletableFuture<>();
            new Thread(new AskThread(future)).start();
            //模拟长时间的计算过程
            Thread.sleep(1000);
            //告知完成结果
            future.complete(60);
        }
    }

在该示例中，启动一个线程，此时AskThread对象还没有拿到它需要的数据，执行到 myRe = re.get() \* re.get()会阻塞。我们用休眠1秒来模拟一个长时间的计算过程，并将计算结果告诉future执行结果，AskThread线程将会继续执行。

public class Calc {
        public static Integer calc(Integer para) {
            try {
                //模拟一个长时间的执行
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return para * para;
        }
    
        public static void main(String[] args) throws ExecutionException, InterruptedException {
            final CompletableFuture<Void> future = CompletableFuture.supplyAsync(() -> calc(50))
                    .thenApply((i) -> Integer.toString(i))
                    .thenApply((str) -> "\"" + str + "\"")
                    .thenAccept(System.out::println);
            future.get();
        }
    }

CompletableFuture.supplyAsync方法构造一个CompletableFuture实例，在supplyAsync()方法中，它会在一个新线程中，执行传入的参数。在这里它会执行calc()方法，这个方法可能是比较慢的，但这并不影响CompletableFuture实例的构造速度，supplyAsync()会立即返回。而返回的CompletableFuture实例就可以作为这次调用的契约，在将来任何场合，用于获得最终的计算结果。supplyAsync用于提供返回值的情况，CompletableFuture还有一个不需要返回值的异步调用方法runAsync(Runnable runnable),一般我们在优化Controller时，使用这个方法比较多。这两个方法如果在不指定线程池的情况下，都是在ForkJoinPool.common线程池中执行，而这个线程池中的所有线程都是Daemon（守护）线程，所以，当主线程结束时，这些线程无论执行完毕都会退出系统。

核心代码：

CompletableFuture.runAsync(() ->
       this.afterBetProcessor(betRequest,betDetailResult,appUser,id)
    );

**异步调用使用Callable来实现**

@RestController  
    public class HelloController {  
      
        private static final Logger logger = LoggerFactory.getLogger(HelloController.class);  
          
        @Autowired  
        private HelloService hello;  
      
        @GetMapping("/helloworld")  
        public String helloWorldController() {  
            return hello.sayHello();  
        }  
      
        /** 
         * 异步调用restful 
         * 当controller返回值是Callable的时候，springmvc就会启动一个线程将Callable交给TaskExecutor去处理 
         * 然后DispatcherServlet还有所有的spring拦截器都退出主线程，然后把response保持打开的状态 
         * 当Callable执行结束之后，springmvc就会重新启动分配一个request请求，然后DispatcherServlet就重新 
         * 调用和处理Callable异步执行的返回结果， 然后返回视图 
         *  
         * @return 
         */  
        @GetMapping("/hello")  
        public Callable<String> helloController() {  
            logger.info(Thread.currentThread().getName() + " 进入helloController方法");  
            Callable<String> callable = new Callable<String>() {  
      
                @Override  
                public String call() throws Exception {  
                    logger.info(Thread.currentThread().getName() + " 进入call方法");  
                    String say = hello.sayHello();  
                    logger.info(Thread.currentThread().getName() + " 从helloService方法返回");  
                    return say;  
                }  
            };  
            logger.info(Thread.currentThread().getName() + " 从helloController方法返回");  
            return callable;  
        }  
    }

**异步调用的方式 WebAsyncTask**

@RestController  
    public class HelloController {  
      
        private static final Logger logger = LoggerFactory.getLogger(HelloController.class);  
          
        @Autowired  
        private HelloService hello;  
      
            /** 
         * 带超时时间的异步请求 通过WebAsyncTask自定义客户端超时间 
         *  
         * @return 
         */  
        @GetMapping("/world")  
        public WebAsyncTask<String> worldController() {  
            logger.info(Thread.currentThread().getName() + " 进入helloController方法");  
      
            // 3s钟没返回，则认为超时  
            WebAsyncTask<String> webAsyncTask = new WebAsyncTask<>(3000, new Callable<String>() {  
      
                @Override  
                public String call() throws Exception {  
                    logger.info(Thread.currentThread().getName() + " 进入call方法");  
                    String say = hello.sayHello();  
                    logger.info(Thread.currentThread().getName() + " 从helloService方法返回");  
                    return say;  
                }  
            });  
            logger.info(Thread.currentThread().getName() + " 从helloController方法返回");  
      
            webAsyncTask.onCompletion(new Runnable() {  
      
                @Override  
                public void run() {  
                    logger.info(Thread.currentThread().getName() + " 执行完毕");  
                }  
            });  
      
            webAsyncTask.onTimeout(new Callable<String>() {  
      
                @Override  
                public String call() throws Exception {  
                    logger.info(Thread.currentThread().getName() + " onTimeout");  
                    // 超时的时候，直接抛异常，让外层统一处理超时异常  
                    throw new TimeoutException("调用超时");  
                }  
            });  
            return webAsyncTask;  
        }  
      
        /** 
         * 异步调用，异常处理，详细的处理流程见MyExceptionHandler类 
         *  
         * @return 
         */  
        @GetMapping("/exception")  
        public WebAsyncTask<String> exceptionController() {  
            logger.info(Thread.currentThread().getName() + " 进入helloController方法");  
            Callable<String> callable = new Callable<String>() {  
      
                @Override  
                public String call() throws Exception {  
                    logger.info(Thread.currentThread().getName() + " 进入call方法");  
                    throw new TimeoutException("调用超时!");  
                }  
            };  
            logger.info(Thread.currentThread().getName() + " 从helloController方法返回");  
            return new WebAsyncTask<>(20000, callable);  
        }  
      
    }

二、增加内嵌Tomcat的最大连接数

@Configuration
    public class TomcatConfig {
        @Bean
        public ConfigurableServletWebServerFactory webServerFactory() {
            TomcatServletWebServerFactory tomcatFactory = new TomcatServletWebServerFactory();
            tomcatFactory.addConnectorCustomizers(new MyTomcatConnectorCustomizer());
            tomcatFactory.setPort(8005);
            tomcatFactory.setContextPath("/api-g");
            return tomcatFactory;
        }
        class MyTomcatConnectorCustomizer implements TomcatConnectorCustomizer {
            public void customize(Connector connector) {
                Http11NioProtocol protocol = (Http11NioProtocol) connector.getProtocolHandler();
                //设置最大连接数               
                protocol.setMaxConnections(20000);
                //设置最大线程数               
                protocol.setMaxThreads(2000);
                protocol.setConnectionTimeout(30000);
            }
        }
    
    }

三、使用@ComponentScan()定位扫包比@SpringBootApplication扫包更快  
四、默认tomcat容器改为Undertow（Jboss下的服务器，Tomcat吞吐量5000，Undertow吞吐量8000）

<exclusions>
            <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
            </exclusion>
    </exclusions>

改为:

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-undertow</artifactId>
    </dependency>

五、使用 BufferedWriter 进行缓冲  
六、Deferred方式实现异步调用

@RestController
    public class AsyncDeferredController {
        private final Logger logger = LoggerFactory.getLogger(this.getClass());
        private final LongTimeTask taskService;
        
        @Autowired
        public AsyncDeferredController(LongTimeTask taskService) {
            this.taskService = taskService;
        }
        
        @GetMapping("/deferred")
        public DeferredResult<String> executeSlowTask() {
            logger.info(Thread.currentThread().getName() + "进入executeSlowTask方法");
            DeferredResult<String> deferredResult = new DeferredResult<>();
            // 调用长时间执行任务
            taskService.execute(deferredResult);
            // 当长时间任务中使用deferred.setResult("world");这个方法时，会从长时间任务中返回，继续controller里面的流程
            logger.info(Thread.currentThread().getName() + "从executeSlowTask方法返回");
            // 超时的回调方法
            deferredResult.onTimeout(new Runnable(){
    		
    			@Override
    			public void run() {
    				logger.info(Thread.currentThread().getName() + " onTimeout");
    				// 返回超时信息
    				deferredResult.setErrorResult("time out!");
    			}
    		});
            
            // 处理完成的回调方法，无论是超时还是处理成功，都会进入这个回调方法
            deferredResult.onCompletion(new Runnable(){
    		
    			@Override
    			public void run() {
    				logger.info(Thread.currentThread().getName() + " onCompletion");
    			}
    		});
            
            return deferredResult;
        }
    }

七、异步调用可以使用AsyncHandlerInterceptor进行拦截

@Component
    public class MyAsyncHandlerInterceptor implements AsyncHandlerInterceptor {
    	
    	private static final Logger logger = LoggerFactory.getLogger(MyAsyncHandlerInterceptor.class);
     
    	@Override
    	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    			throws Exception {
    		return true;
    	}
     
    	@Override
    	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
    			ModelAndView modelAndView) throws Exception {
    //		HandlerMethod handlerMethod = (HandlerMethod) handler;
    		logger.info(Thread.currentThread().getName()+ "服务调用完成，返回结果给客户端");
    	}
     
    	@Override
    	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
    			throws Exception {
    		if(null != ex){
    			System.out.println("发生异常:"+ex.getMessage());
    		}
    	}
     
    	@Override
    	public void afterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response, Object handler)
    			throws Exception {
    		
    		// 拦截之后，重新写回数据，将原来的hello world换成如下字符串
    		String resp = "my name is chhliu!";
    		response.setContentLength(resp.length());
    		response.getOutputStream().write(resp.getBytes());
    		
    		logger.info(Thread.currentThread().getName() + " 进入afterConcurrentHandlingStarted方法");
    	}
     
    }

参考：[https://my.oschina.net/u/3768341/blog/3001731][https_my.oschina.net_u_3768341_blog_3001731]  
参考：[https://blog.csdn.net/liuchuanhong1/article/details/78744138][https_blog.csdn.net_liuchuanhong1_article_details_78744138]

[https_my.oschina.net_u_3768341_blog_3001731]: https://my.oschina.net/u/3768341/blog/3001731
[https_blog.csdn.net_liuchuanhong1_article_details_78744138]: https://blog.csdn.net/liuchuanhong1/article/details/78744138