部署时出现502代理错误

我现在正在研究Java Web项目.它在使用eclipse和Tomcat的本地主机上运行良好.但是，当我将war文件部署到远程服务器(也是tomcat)时，前端的一个函数返回502代理错误.

I am now working on a Java web project. It works well in local host using eclipse and Tomcat. But when I deploy the war file to remote server (which is also tomcat), one function at front end return 502 proxy error.

该功能请求我部署的服务器，并且该服务器将进一步请求另一台远程服务器.整个过程大约需要2分钟.我还检查了部署日志.除返回前端外，服务器似乎运行良好.

The function requests the server that I deployed and the server will further request another remote server. The whole process will take around 2 minutes. I also check the deployment log. It seems that the server is working well except for returning to front end.

有人以前有类似的问题吗?

Does anyone have similar problem before?