Nginx报错 connect() failed (111: Connection refused) while connecting to upstream 的解决方法

Nginx报错 connect() failed (111: Connection refused) while connecting to upstream 的解决方法

参考文章：

（1）Nginx报错 connect() failed (111: Connection refused) while connecting to upstream 的解决方法

（2）https://www.cnblogs.com/zhangxiaoliu/p/5086734.html

备忘一下。