0

Our server returns ads to the publisher's app (android/iOS apps). Let's consider this case where the returned ad is an HTML with img tags containing remote images (resources stored in third party servers of ad networks). Something like this - 

    <!DO CTYPE html> 
<html>
   <head>
      <meta http-equiv="content-type" content="text/html; charset=UTF-8">
      <meta charset="UTF-8">
      <title>Untitled Document</title>
      <style> #ad{ margin: 0px auto 0 auto; width: 308px; padding: 5px; height: 38px; border: 1px solid #ddd; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; background-color:#fff; text-align:left; } #ad h3{ padding: 0; margin: 0; color:#0067FF; font-weight: normal; font-size: 12px; } #ad a { color:#009C00; font-size: 10px; text-decoration:none; margin: 0; padding: 0; } #ad p.description { margin: 0; padding: 0; font-size: 8px; margin-bottom: 10px; } .ad_label{ margin: 0 auto 0 auto; text-align: center; color: #a09f9f; font-size: 12px; padding: 3px 0 0 0; } </style>
   </head>
   <body>
      <div id="ad">
         <h3>Junk-A-Car</h3>
         <a href="http://bridge.ame.admarketplace.net/ct?version=15.0.0&key=1431522124104100072.54&ci=1431522124597.10964">yp.com/reviews</a> 
         <p class="description">Find Local Automobile Salvage Need Help? Click Here!</p>
      </div>
      <img src="http://imp.admarketplace.net/imp?id=7R7wxEzkiFdwxr3NJGbzfQbX4BkW4BkXfYbW1C\WfQ\W4p\W4pH+7RcdIG7+GmwqgClkfZldfQ8XfQ2Xfp2XfpbW4Z8nxnEZGmzYI=EYgCbnHF3QJre+GmwqgClrfpf+fCDW7ncQHmzdJR3KiF2zfQld4C2nimE+jmzYIczvIpkY4Zq+fp8Yfp2nxr7kgCbnxGEwxRwKj=EYJCdQHG7Z7nckxZkX1CbZfQxZ1pHnHncZIEzQx=fzfBaafpbnHF4kjFcTGm4WHZkX5QLWftInIFEqGr4wxRIwxQdw5GNuJtkkfBIdxr7KImEVGmwqgGTOxY8PfCDX5t7Q8Q\kfZ2T8n4V8Q\Y5t7q8Q\dfplT8R\O1QlXfQfrKBIWjF7KiF2zfCb+4Q2nHnwqI=EYGmwqgCby" width="1" height="1" /> 
   </body>
</html>
<img src="http://54.204.70.10/fam/view.php?p=__pid=4e17aeb00411789d__sid=102175__bid=1259380__cb=e56d08f1c9__h=1431522124__acp=800660a03aab58e96ec93211c5fc5db6__s=f398b7b975fb896b27fed55d213f6687" alt="" width="1" height="1" />

Questions

Do the images resources get cached, by default, on client side and the same get rendered on subsequent ad requests? If not, can it be enforced from server side, by passing "necessary" headers?

I tried testing with fiddler, and always observed "200 Ok" status being displayed for same images. How do I know when a cached image is loaded?

Updates

Updated ad response format - HTML format.

Sandeepan Nath
  • 9,966
  • 17
  • 86
  • 144

1 Answers1

0

The server generatng the HTTP protocol response is responsible for sending cache control headers along with it indicating whether it is permitted to be cached and if so whether the server needs to be informed before each use.

This blog begginners guide is a good place to start for details. Then move on to the RFC 7234 caching specification itself

Community
  • 1
  • 1
Amos Jeffries
  • 191
  • 3