Nginx resolve配置冲突

1. 当nginx upstream里边同时配置resolve和check模块 ，nginx会奔溃
比如：

upstream npss {

        server www.a.com:80   resolve;
        check interval=3000 rise=2 fall=2 timeout=1000;

}

2. 当nginx upstream里边同时配置resolve和backup时，nginx也会奔溃
比如：

upstream npss {

        server www.a.com:80   resolve;
        server www.b.com:80  backup  resolve;

}