Testing CDN Consistency with bash date time curl while loop

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This is a simple one. Soa customer was complaining that after 3 minutes the cache time of the file on his CDN was changing. I wanted to built a way to test the consistency of the requests. Here is how I did it.

file curl-format.txt

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

Short, simple, and to the point;

while ((1!=0)); do date; curl -w "@curl-format.txt" -o /dev/null -s "https://www.somecdndomain.secure.raxcdn.com/img/upload/3someimage_t32337827238.jpg"; done;

Output looks like:

                    ----------
         time_total:  0.395
Tue Feb  9 09:03:28 UTC 2016
      time_namelookup:  0.151
       time_connect:  0.154
    time_appconnect:  0.332
   time_pretransfer:  0.333
      time_redirect:  0.000
 time_starttransfer:  0.338
                    ----------
         time_total:  0.351
Tue Feb  9 09:03:28 UTC 2016
      time_namelookup:  0.151
       time_connect:  0.154
    time_appconnect:  0.324
   time_pretransfer:  0.324
      time_redirect:  0.000
 time_starttransfer:  0.331
                    ----------
         time_total:  0.347
Tue Feb  9 09:03:29 UTC 2016
      time_namelookup:  0.151
       time_connect:  0.154
    time_appconnect:  0.385
   time_pretransfer:  0.385
      time_redirect:  0.000
 time_starttransfer:  0.391
                    ----------
         time_total:  0.404
Tue Feb  9 09:03:29 UTC 2016
      time_namelookup:  0.151
       time_connect:  0.155
    time_appconnect:  0.348
   time_pretransfer:  0.349
      time_redirect:  0.000
 time_starttransfer:  0.357
                    ----------
         time_total:  0.374
Tue Feb  9 09:03:30 UTC 2016
      time_namelookup:  0.151
       time_connect:  0.155
    time_appconnect:  0.408
   time_pretransfer:  0.409
      time_redirect:  0.000
 time_starttransfer:  0.417
                    ----------
         time_total:  0.433
Tue Feb  9 09:03:30 UTC 2016

pretty handy andy.

With headers

# while ((1!=0)); do date; curl -IL -w "@curl-format.txt" -s "https://www.scdn3.secure.raxcdn.com/img/upload/3_sdsdsds6a9e80df0baa19863ffb8.jpg"; sleep 180; done;