1. 创建如下的一个文件：

$ vim curl-format.txt

time_namelookup: %{time_namelookup}\n
time_connect: %{time_connect}\n
time_appconnect: %{time_appconnect}\n
time_redirect: %{time_redirect}\n
time_pretransfer: %{time_pretransfer}\n
time_starttransfer: %{time_starttransfer}\n
----------\n
time_total: %{time_total}\n

2.利用curl请求目标域名，就可以得到处理各个阶段的耗时情况：

curl -w "@curl-format.txt" -o /dev/null -s -L "https://www.example.com"

time_namelookup: 0.012
time_connect: 0.182
time_appconnect: 0.718
time_redirect: 0.000
time_pretransfer: 0.718
time_starttransfer: 0.887
----------
time_total: 0.887

参考

K8S – 优化dns解析时间
https://www.cnblogs.com/evenchen/p/12124992.html