limit_zone   one  $binary_remote_addr  10m;

limit_conn one 5;
limit_rate 50k;

http{
    .............
    limit_zone   one  $binary_remote_addr  10m;  #添加这一行
    ..............
    server{
         .................
         location {
             .........
             limit_conn one 5;          #连接数限制（线程）
             limit_rate 50k;            #带宽限制
             ........
         }
        .................
    }
    .............
}