title: Tricky Issue Handling File Upload in Perl
body: <p>We use CGI.pm to help us handle file uploading on our website and through our API which is used by our Android &amp; iPhone Apps. We recently noticed that CGI.pm seems to be returning no params for almost 50% of the files being uploaded via our iPhone App. We haven't seen a similar issue with those files being uploaded via our website.</p>
  
  <p>We can't replicate the problem in testing but in production the cgi_error() method of CGI.pm isn't reporting any errors in those cases where the CGI.pm params are missing. We have confirmed that the iPhone App is always including the correct params when POSTing the files for upload.</p>
  
  <p>Quick background on the setup. We have the application delpoyed on Amazon EC2 Servers which are being load balanced using the Amazon Elastic Load Balancers. We also have $CGI::POST_MAX=(1024*100000); so the POST max size is set to 100MB and we have confirmed that all uploads are under this limit.</p>
  
  <p>I'm not sure where to go next. Any ideas on what the issue might be and how to resolve it would be great appreciated. Also helpful would be any ideas on how to identify the root of the issue so we can start troubleshooting.</p>
  
  <p>Thanks in advance for your help!</p>