在 spring-cloud-openfeign 中设置最大可用连接

如何解决在 spring-cloud-openfeign 中设置最大可用连接

试图找出如何在 spring-cloud-feign 中限制每台主机的最大可用连接数。

有一个简单的 Spring Boot 应用程序，它只向自身发送和记录请求。试图设置下一个配置来限制连接池，但看起来它被忽略了：

feign.httpclient.max-connections-per-route=2
feign.httpclient.max-connections=2

有一个并行流，它请求一个虚拟服务器并在收到响应后写入日志。服务器在发送响应之前挂起 5 秒。

查看日志文件，我可以看到同时发出了 12 个请求。由我的 PC 的逻辑核心数决定。

2021-04-02 16:33:39.521 [http-nio-8081-exec-6] INFO  o.s.web.servlet.DispatcherServlet - Completed initialization in 1 ms
2021-04-02 16:33:44.580 [ForkJoinPool.commonPool-worker-23] INFO  com.example.springdemo.TestClient - made '156' request
2021-04-02 16:33:44.580 [ForkJoinPool.commonPool-worker-19] INFO  com.example.springdemo.TestClient - made '327' request
2021-04-02 16:33:44.580 [ForkJoinPool.commonPool-worker-7] INFO  com.example.springdemo.TestClient - made '406' request
2021-04-02 16:33:44.580 [ForkJoinPool.commonPool-worker-21] INFO  com.example.springdemo.TestClient - made '577' request
2021-04-02 16:33:44.580 [ForkJoinPool.commonPool-worker-13] INFO  com.example.springdemo.TestClient - made '827' request
2021-04-02 16:33:44.580 [ForkJoinPool.commonPool-worker-31] INFO  com.example.springdemo.TestClient - made '452' request
2021-04-02 16:33:44.582 [ForkJoinPool.commonPool-worker-17] INFO  com.example.springdemo.TestClient - made '31' request
2021-04-02 16:33:44.582 [ForkJoinPool.commonPool-worker-5] INFO  com.example.springdemo.TestClient - made '906' request
2021-04-02 16:33:44.582 [ForkJoinPool.commonPool-worker-27] INFO  com.example.springdemo.TestClient - made '968' request
2021-04-02 16:33:44.582 [ForkJoinPool.commonPool-worker-9] INFO  com.example.springdemo.TestClient - made '77' request
2021-04-02 16:33:44.582 [ForkJoinPool.commonPool-worker-3] INFO  com.example.springdemo.TestClient - made '15' request
2021-04-02 16:33:44.583 [main] INFO  com.example.springdemo.TestClient - made '656' request

我错过了什么吗？

这是我为重现问题而制作的应用程序：

使用假客户端的一段代码：

    public void tryParallelInvocation() {
        IntStream.range(0,1000)
                .parallel()
                .forEach(value -> {
                    feignClient.testRequest(String.valueOf(value));
                    LOG.info("made '" + value + "' request");
                });
    }

Feign 客户端界面：

@FeignClient(value = "default",url = "http://localhost:8081/")
public interface TestFeignClient {

    @GetMapping("/demo")
    String testRequest(@RequestParam("param") String param);

}

REST 端点：

    @GetMapping
    public ResponseEntity<String> demo(@RequestParam(value = "param") String param) {
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return ResponseEntity.ok(param);
    }

依赖：

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.4</version>
        <relativePath/>
    </parent>
...
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
        </dependency>

application.properties：

server.port=8081
feign.httpclient.max-connections-per-route=2
feign.httpclient.max-connections=2
feign.httpclient.enabled=true