springCloud中最重要的就是微服务之间的调用，因为网络延迟或者调用超时会直接导致程序异常，因此超时的配置及处理就至关重要。

在开发过程中被调用的微服务打断点发现会又多次重试的情况，测试环境有的请求响应时间过长也会出现多次请求，网上查询了配置试了一下无果，决定自己看看源码。
本人使用的SpringCloud版本是Camden.SR3。

微服务间调用其实走的是http请求，debug了一下默认的ReadTimeout时间为5s，ConnectTimeout时间为2s，我使用的是Fegin进行微服务间调用，底层用的还是Ribbon，网上提到的配置如下

ribbon:
  ReadTimeout: 60000
  ConnectTimeout: 60000
  MaxAutoRetries: 0
  MaxAutoRetriesNextServer: 1

@PostMapping("/testa")
    public Integer testee(){
        try {
            Thread.sleep(8000L);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return 9;
    }

Object executeAndDecode(RequestTemplate template) throws Throwable {
    Request request = targetRequest(template);
    if (logLevel != Logger.Level.NONE) {
      logger.logRequest(metadata.configKey(), logLevel, request);
    }
    Response response;
    long start = System.nanoTime();
    try {
      response = client.execute(request, options);
      response.toBuilder().request(request).build();
    } catch (IOException e) {
      if (logLevel != Logger.Level.NONE) {
        logger.logIOException(metadata.configKey(), logLevel, e, elapsedTime(start));
      }
     //出现异常后抛出RetryableException
      throw errorExecuting(request, e);
    }

@Override
  public Object invoke(Object[] argv) throws Throwable {
    RequestTemplate template = buildTemplateFromArgs.create(argv);
    Retryer retryer = this.retryer.clone();
    while (true) {
      try {
        return executeAndDecode(template);
      } catch (RetryableException e) {
         //重试的地方
        retryer.continueOrPropagate(e);
        if (logLevel != Logger.Level.NONE) {
          logger.logRetry(metadata.configKey(), logLevel);
        }
        continue;
      }
    }
  }

public Default() {
      this(100, SECONDS.toMillis(1), 5);
    }

第一个参数period是请求重试的间隔算法参数，第二个参数maxPeriod 是请求间隔最大时间，第三个参数是重试的次数。算法如下：

long nextMaxInterval() {
      long interval = (long) (period * Math.pow(1.5, attempt - 1));
      return interval > maxPeriod ? maxPeriod : interval;
    }

新建一个配置类

@Configuration
public class FeginConfig {
    @Bean
    public Retryer feginRetryer(){
        Retryer retryer = new Retryer.Default(100, SECONDS.toMillis(10), 3);
        return retryer;
    }
}

@FeignClient(value = http://www.mamicode.com/"fund-server",fallback = FundClientHystrix.class,configuration = FeginConfig.class)
public interface FundClient

@Override
    public Response execute(Request request, Request.Options options) throws IOException {
        try {
            URI asUri = URI.create(request.url());
            String clientName = asUri.getHost();
            URI uriWithoutHost = cleanUrl(request.url(), clientName);
            FeignLoadBalancer.RibbonRequest ribbonRequest = new FeignLoadBalancer.RibbonRequest(
                    this.delegate, request, uriWithoutHost);
                     //请求参数
            IClientConfig requestConfig = getClientConfig(options, clientName);
            return lbClient(clientName).executeWithLoadBalancer(ribbonRequest,
                    requestConfig).toResponse();
        }
        catch (ClientException e) {
            IOException io = findIOException(e);
            if (io != null) {
                throw io;
            }
            throw new RuntimeException(e);
        }
    }

ribbon:
  ReadTimeout: 60000
  ConnectTimeout: 60000
  MaxAutoRetries: 0
  MaxAutoRetriesNextServer: 1

@Bean
    public Request.Options feginOption(){
        Request.Options option = new Request.Options(7000,7000);
        return option;
    }