springcloud之Feign超时问题(Read timed out executing POST http://***)

左手的ㄟ右手 2022-03-09 14:11 275阅读 0赞

## 问题背景 ##

最近公司项目有个功能需进行三层Feign调用，且还要调外部接口，延迟挺大，造成Feign一直提示`Read timed out executing POST`。

feign.RetryableException: Read timed out executing POST http://******
            at feign.FeignException.errorExecuting(FeignException.java:67)
            at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:104)
            at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:76)
            at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:103)
            at com.sun.proxy.$Proxy113.getBaseRow(Unknown Source)
    Caused by: java.net.SocketTimeoutException: Read timed out
            at java.net.SocketInputStream.socketRead0(Native Method)
            at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
            at java.net.SocketInputStream.read(SocketInputStream.java:170)
            at java.net.SocketInputStream.read(SocketInputStream.java:141)
            at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
            at java.io.BufferedInputStream.read1(BufferedInputStream.java:286)
            at java.io.BufferedInputStream.read(BufferedInputStream.java:345)
            at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:704)
            at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:647)
            at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1569)
            at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
            at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
            at feign.Client$Default.convertResponse(Client.java:152)
            at feign.Client$Default.execute(Client.java:74)

## 解决方案 ##

首先，我们看下Feign的简介

> Feign 是一个声明式的web服务客户端，这便得编写web服务客户端更容易，使用Feign 创建一个接口并对它进行注解，它具有可插拔的注解支持包括Feign注解与JAX-RS注解，Feign还支持可插拔的编码器与解码器，Spring Cloud 增加了对 Spring MVC的注解，Spring Web 默认使用了HttpMessageConverters, Spring Cloud `集成 Ribbon 和 Eureka` 提供的负载均衡的HTTP客户端 Feign.

这么说吧，Feign接口调用分两层，`Ribbon的调用`和`Hystrix调用`，理论上`设置Ribbon的时间`即可，但是Ribbon的超时时间和Hystrix的超时时间需要结合起来，按照`木桶原则`最低的就是Feign的超时时间，建议最好配置`超时时间一致`。经过配置一下application设置后，完美解决了问题。因为第三方接口中需要3~20秒不等的时间，所以这个数值也是根据自己的业务系统情况设置的。

## application.xml ##

#hystrix的超时时间
    hystrix:
        command:
            default:
                execution:
                  timeout:
                    enabled: true
                  isolation:
                        thread:
                            timeoutInMilliseconds: 30000
    #ribbon的超时时间
    ribbon:
      ReadTimeout: 30000
      ConnectTimeout: 30000