在默认配置中，Spring Webflux似乎将并行请求的数量限制为256。
我的设置有一个非常简单的控制器：
@RestController
public class SimpleRestController {
private final Log logger = LogFactory.getLog(getClass());
private AtomicLong countEnter = new AtomicLong(0);
private AtomicLong countExit = new AtomicLong(0);
@GetMapping(value = "/delayed")
public Mono<String> delayed() {
logger.info("delayed ENTER " + countEnter.incrementAndGet());
return Mono.just("result").delayElement(Duration.ofSeconds(60))
.doOnNext(s -> logger.info("delayed EXIT " + countExit.incrementAndGet()));
}
}
该配置仅启用WebFlux：
@SpringBootConfiguration
@EnableWebFlux
public class SearchServiceConfiguration {
}
依赖项很少：
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>10</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>10</source>
<target>10</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
我用此脚本并行调用端点：
#!/usr/bin/env bash
for p in `seq 1 1000`;
do
curl -s http://localhost:8080/delayed &
done
wait
echo "All done"
对于第257个请求，返回Resource temporarily unavailable。
哪个设置限制了并行请求的数量？
这是产生的日志输出：
2018-10-26 14:27:27.253 INFO 23728 --- [ main] s.w.r.r.m.a.RequestMappingHandlerMapping : Mapped "{[/sleep],methods=[GET],produces=[application/stream+json]}" onto public java.lang.String controller.SimpleRestController.sleep() throws java.lang.InterruptedException
2018-10-26 14:27:27.253 INFO 23728 --- [ main] s.w.r.r.m.a.RequestMappingHandlerMapping : Mapped "{[/delayed],methods=[GET]}" onto public reactor.core.publisher.Mono<java.lang.String> controller.SimpleRestController.delayed()
2018-10-26 14:27:27.315 INFO 23728 --- [ main] o.s.w.r.r.m.a.ControllerMethodResolver : Looking for @ControllerAdvice: org.springframework.boot.web.reactive.context.AnnotationConfigReactiveWebServerApplicationContext@3cdf2c61: startup date [Fri Oct 26 14:27:26 CEST 2018]; root of context hierarchy
2018-10-26 14:27:27.639 INFO 23728 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-10-26 14:27:27.938 INFO 23728 --- [ctor-http-nio-1] r.ipc.netty.tcp.BlockingNettyContext : Started HttpServer on /0:0:0:0:0:0:0:0:8080
2018-10-26 14:27:27.939 INFO 23728 --- [ main] o.s.b.web.embedded.netty.NettyWebServer : Netty started on port(s): 8080
2018-10-26 14:27:27.943 INFO 23728 --- [ main] d.h.s.s.SimpleApplication : Started SimpleApplication in 1.548 seconds (JVM running for 2.396)
2018-10-26 14:27:34.295 INFO 23728 --- [ctor-http-nio-5] d.h.s.s.controller.SimpleRestController : delayed ENTER 2
2018-10-26 14:27:34.295 INFO 23728 --- [ctor-http-nio-3] d.h.s.s.controller.SimpleRestController : delayed ENTER 1
2018-10-26 14:27:34.295 INFO 23728 --- [ctor-http-nio-4] d.h.s.s.controller.SimpleRestController : delayed ENTER 4
2018-10-26 14:27:34.295 INFO 23728 --- [ctor-http-nio-2] d.h.s.s.controller.SimpleRestController : delayed ENTER 3
2018-10-26 14:27:34.324 INFO 23728 --- [ctor-http-nio-6] d.h.s.s.controller.SimpleRestController : delayed ENTER 5
2018-10-26 14:27:34.351 INFO 23728 --- [ctor-http-nio-7] d.h.s.s.controller.SimpleRestController : delayed ENTER 6
2018-10-26 14:27:34.381 INFO 23728 --- [ctor-http-nio-8] d.h.s.s.controller.SimpleRestController : delayed ENTER 7
2018-10-26 14:27:34.413 INFO 23728 --- [ctor-http-nio-1] d.h.s.s.controller.SimpleRestController : delayed ENTER 8
2018-10-26 14:27:34.438 INFO 23728 --- [ctor-http-nio-2] d.h.s.s.controller.SimpleRestController : delayed ENTER 9
2018-10-26 14:27:34.466 INFO 23728 --- [ctor-http-nio-3] d.h.s.s.controller.SimpleRestController : delayed ENTER 10
2018-10-26 14:27:34.497 INFO 23728 --- [ctor-http-nio-4] d.h.s.s.controller.SimpleRestController : delayed ENTER 11
2018-10-26 14:27:34.526 INFO 23728 --- [ctor-http-nio-5] d.h.s.s.controller.SimpleRestController : delayed ENTER 12
2018-10-26 14:27:34.561 INFO 23728 --- [ctor-http-nio-6] d.h.s.s.controller.SimpleRestController : delayed ENTER 13
2018-10-26 14:27:34.594 INFO 23728 --- [ctor-http-nio-7] d.h.s.s.controller.SimpleRestController : delayed ENTER 14
...
2018-10-26 14:27:42.675 INFO 23728 --- [ctor-http-nio-6] d.h.s.s.controller.SimpleRestController : delayed ENTER 253
2018-10-26 14:27:42.711 INFO 23728 --- [ctor-http-nio-7] d.h.s.s.controller.SimpleRestController : delayed ENTER 254
2018-10-26 14:27:42.745 INFO 23728 --- [ctor-http-nio-8] d.h.s.s.controller.SimpleRestController : delayed ENTER 255
2018-10-26 14:27:42.774 INFO 23728 --- [ctor-http-nio-1] d.h.s.s.controller.SimpleRestController : delayed ENTER 256
2018-10-26 14:28:04.312 INFO 23728 --- [ parallel-3] d.h.s.s.controller.SimpleRestController : delayed EXIT 1
2018-10-26 14:28:04.312 INFO 23728 --- [ parallel-2] d.h.s.s.controller.SimpleRestController : delayed EXIT 2
2018-10-26 14:28:04.321 INFO 23728 --- [ parallel-2] d.h.s.s.controller.SimpleRestController : delayed EXIT 3
2018-10-26 14:28:04.321 INFO 23728 --- [ parallel-2] d.h.s.s.controller.SimpleRestController : delayed EXIT 4
2018-10-26 14:28:04.333 INFO 23728 --- [ parallel-4] d.h.s.s.controller.SimpleRestController : delayed EXIT 5
2018-10-26 14:28:04.359 INFO 23728 --- [ parallel-5] d.h.s.s.controller.SimpleRestController : delayed EXIT 6
2018-10-26 14:28:04.389 INFO 23728 --- [ parallel-6] d.h.s.s.controller.SimpleRestController : delayed EXIT 7
2018-10-26 14:28:04.421 INFO 23728 --- [ parallel-7] d.h.s.s.controller.SimpleRestController : delayed EXIT 8
2018-10-26 14:28:04.446 INFO 23728 --- [ parallel-8] d.h.s.s.controller.SimpleRestController : delayed EXIT 9
2018-10-26 14:28:04.474 INFO 23728 --- [ parallel-1] d.h.s.s.controller.SimpleRestController : delayed EXIT 10
2018-10-26 14:28:04.505 INFO 23728 --- [ parallel-2] d.h.s.s.controller.SimpleRestController : delayed EXIT 11
...
2018-10-26 14:28:12.570 INFO 23728 --- [ parallel-1] d.h.s.s.controller.SimpleRestController : delayed EXIT 250
2018-10-26 14:28:12.607 INFO 23728 --- [ parallel-2] d.h.s.s.controller.SimpleRestController : delayed EXIT 251
2018-10-26 14:28:12.643 INFO 23728 --- [ parallel-3] d.h.s.s.controller.SimpleRestController : delayed EXIT 252
2018-10-26 14:28:12.683 INFO 23728 --- [ parallel-4] d.h.s.s.controller.SimpleRestController : delayed EXIT 253
2018-10-26 14:28:12.719 INFO 23728 --- [ parallel-5] d.h.s.s.controller.SimpleRestController : delayed EXIT 254
2018-10-26 14:28:12.752 INFO 23728 --- [ parallel-6] d.h.s.s.controller.SimpleRestController : delayed EXIT 255
2018-10-26 14:28:12.782 INFO 23728 --- [ parallel-7] d.h.s.s.controller.SimpleRestController : delayed EXIT 256
答案 0 :(得分：6)
这不是我在本地设置中看到的内容。将您的控制器更改为以下内容会打印“ onNext 1”到“ onNext 1000”：
textvalue在您的评论之一中，您提到AtomicLong count = new AtomicLong(0);
@GetMapping("/delayed")
public Mono<String> delayed() {
return Mono.just("result").delayElement(Duration.ofSeconds(30))
.doOnNext(s -> {
logger.info("onNext " + count.incrementAndGet());
});
}
，它是Servlet特定的。这告诉我您不是运行Spring WebFlux应用程序，而是实际上是Spring MVC应用程序。如果您正在运行Spring Boot，并且在类路径上有Spring MVC，则Spring Boot will configure a Spring MVC application for you。
默认情况下，Spring MVC将使用CommonsRequestLoggingFilter来调度那些请求的异步处理（Spring MVC支持反应性返回类型，但会将它们视为SimpleAsyncTaskExecutor请求，asynchronous but not non-blocking）。我认为@Async默认没有并发限制。也许您在应用程序中配置了将并发限制为256的任务执行器？
我尝试使用Spring MVC应用程序重现该问题，但仍然在日志中处理了999个请求和一个已解决的异常：
SimpleAsyncTaskExecutor答案 1 :(得分：1)
服务器不是您的限制因素。该错误表明由于资源限制，创建后台进程失败。有几种可能的原因：