title: IIS Compression For WebService Returning a Large String Value
body: <p>I have a web service returning an XML value in a String format.</p>
  
  <p>Through IE9, I can see that some of the size for the web service calls go as high as 1MB.</p>
  
  <p>I enabled compression in IIS 6 by editing the Metabase.xml file, setting the following:</p>
  
  <pre><code>HcScriptFileExtensions = "asmx"
  </code></pre>
  
  <p>under the </p>
  
  <pre><code>IIsCompressionScheme    Location ="/LM/W3SVC/Filters/Compression/gzip"
  </code></pre>
  
  <p>I have also enabled HTTP Compression on the Service tab for the Web Sites properties in IIS Manager.</p>
  
  <p>I have also added the HttCompression in the web service extensions, mapping to the gzip dll on the Windows\System32\inetsrv\ folder.</p>
  
  <p>When I make the call to the web service, the value being returned is not compressed (the same size as with the service call before).</p>
  
  <p>Any tips to ensure that IIS compresses the string data value being returned by IIS?</p>
  
  <p>Update:
  I also followed the instructions on these links:</p>
  
  <p><a href="http://rextang.net/blogs/work/archive/2007/09/12/5654.aspx" rel="nofollow">http://rextang.net/blogs/work/archive/2007/09/12/5654.aspx</a>
  http://blogs.msdn.com/b/rextang/archive/2007/09/13/4880187.aspx</p>
  
  <p>Using IE9, I from the Developer Tools, checking the detailed view of the web service call, I can see that the Accept-Encoding key has a value of gzip/deflate.</p>
  
  <p>The web service SOAP XML (in String) value is still not being compressed. Any areas where I should be looking further?</p>
  
  <p>By the way, I am using IIS6.</p>
  
  <p>Update:
  I checked this site:
  <a href="http://blogs.iis.net/webtopics/archive/2009/02/24/troubleshooting-http-compression-in-iis-6-0.aspx" rel="nofollow">http://blogs.iis.net/webtopics/archive/2009/02/24/troubleshooting-http-compression-in-iis-6-0.aspx</a></p>
  
  <p>I got items 1,2,3 properly.</p>
  
  <p>For item 4, I even tried only setting asmx as extension but to no avail.</p>
  
  <p>For item 5, I don't have any compression setting at a child level.</p>
  
  <p>For item 6, the antivirus does not make a scan on the directory for compression.</p>
  
  <p>For item 7, I am passing no slash as parameter on the executing DLL.</p>
  
  <p>For item 8, I am unsure where/how to check for this.</p>
  
  <p>For item 9, I have checked with fiddler and the proper headers are being placed on the request headers.</p>
  
  <p>For item 10, I don't see any settings in my apps that would require touching this.</p>
  
  <p>For item 11, status code I am receiving is 200.</p>
  
  <p>For item 12, the app is accessed with no proxy specified.</p>
  
  <p>For item 13, the request is a web service.</p>