服务器回复巨大响应时，IE 9挂起

Question

I am testing download functionality for which I have written a php script. This script reads a large file (10MB) using fopen and fread. Using fread I am reading a chunk of 10MB in a buffer and that buffer I am echoing and then flushing out using flush and ob_flush functions. So that client receives this buffer and I am able to check number of bytes received. This works fine in Chrome, FireFox and IE 8 but when I tested it in IE 9, the browser hangs and I am not able to get the proper downloaded bytes. Can someone suggest what are the other options that we can use to test this?

  define('CHUNK_SIZE', 1024*10240);
  $handle=fopen("10MBFile", 'rb');
  $buffer=fread($handle, CHUNK_SIZE);
  echo $buffer;
  ob_flush();
  flush();

Regds

Answer 1

I had numerous strange hangups with IE9+ and apache and could fix it with adding this stuff into httpd.conf :

# Deal with user agents that deliberately violate open standards
#
<IfModule setenvif_module>
BrowserMatch "MSIE 10.0;" bad_DNT
</IfModule>
<IfModule headers_module>
RequestHeader unset DNT env=bad_DNT
</IfModule>
AcceptFilter https none 
AcceptFilter http none 
EnableSendfile Off 
EnableMMAP off