IIS Compression in IIS6.0

IIS 7 Compression. Good? Bad? How much?

Scott Forsyth's Blog — Mon, 23 Feb 2009 06:09:26 GMT

If you haven't properly leveraged compression in IIS, you're missing out on a lot! Compression is a trade

IIS6 Compression: other tidbits « You’re a smart guy, figure it out!

IIS6 Compression: other tidbits « You’re a smart guy, figure it out! — Tue, 22 Apr 2008 06:16:02 GMT

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re: IIS Compression in IIS6.0

Howard — Sun, 29 Jul 2007 15:44:47 GMT

Does anyone know my all my .aspx pages show a size of "-1" when gzip is enabled in IIS6? Any tips appreciated. Thanks.

re: IIS Compression in IIS6.0

Andy M — Thu, 07 Jun 2007 18:16:30 GMT

We are working in WSS3 and MOSS 2007 environment.

We are trying to figure out how to display large pdf files in the brower as fast as possible. I've been trying to research page at a time or byte serving. Does anyone know about how IIS and sharepoint work with this? Also do you have any good articles or information i can read?

Thanks in advance, Andy

re: IIS Compression in IIS6.0

Yezdaan — Wed, 30 May 2007 16:01:52 GMT

This article was great on explaining the server side. However, if you want to use webservices with anything but a webbrowser, here is some code that will help:

I found some code online that with some bug fixes works well as a HttpWebResponse decompressed:

using System.Net;

using System.IO;

using System.IO.Compression;

namespace ClientsDataType

{

public class HttpWebResponseDecompressed : WebResponse

{

private HttpWebResponse response;

public HttpWebResponseDecompressed(WebResponse wResponse)

{

response = (HttpWebResponse)wResponse;

}

public override void Close()

{

response.Close();

}

public override Stream GetResponseStream()

{

Stream compressedStream = null;

if (response.ContentEncoding == "gzip")

{

compressedStream = new

GZipStream(response.GetResponseStream(), CompressionMode.Decompress, false);

}

else if (response.ContentEncoding == "deflate")

{

compressedStream = new

DeflateStream(response.GetResponseStream(), CompressionMode.Decompress, false);

}

if (compressedStream != null)

{

// Decompress

MemoryStream decompressedStream = new MemoryStream();

int size = 2048;

byte[] writeData = new byte[2048];

while (size > 0)

{

size = compressedStream.Read(writeData, 0, size);

decompressedStream.Write(writeData, 0, size);

}

decompressedStream.Seek(0, SeekOrigin.Begin);

compressedStream.Close();

return decompressedStream;

}

else

return response.GetResponseStream();

}

public override long ContentLength

{

get { return response.ContentLength; }

}

public override string ContentType

{

get { return response.ContentType; }

}

public override System.Net.WebHeaderCollection Headers

{

get { return response.Headers; }

}

public override System.Uri ResponseUri

{

get { return response.ResponseUri; }

}

Now that you have a class that will decompress your web reponse, all you need is to override a couple methods in your proxy to make it work. (I wish Microsoft would update the proxy creation process to support compression, but right now it doesnt)

Namespace ChatImplementation

Partial Public Class ChatImplementation

Protected Overrides Function GetWebRequest(ByVal uri As System.Uri) As System.Net.WebRequest

Dim request As System.Net.WebRequest = MyBase.GetWebRequest(uri)

request.Headers.Add("Accept-Encoding", "gzip, deflate")

Return request

End Function

Protected Overrides Function GetWebResponse(ByVal request As System.Net.WebRequest) As System.Net.WebResponse

Dim response As HttpWebResponseDecompressed = New _

HttpWebResponseDecompressed(MyBase.GetWebResponse(request))

Return response

End Function

Protected Overrides Function GetWebResponse(ByVal request As System.Net.WebRequest, ByVal result As System.IAsyncResult) As System.Net.WebResponse

Dim response As HttpWebResponseDecompressed = New _

HttpWebResponseDecompressed(MyBase.GetWebResponse(request, result))

Return response

End Function

End Class

End Namespace

But the important thing is the use of partial classes. This means even if we update our web proxy, it doesn't blow out this code everytime.

I got both the sync and async code working, the later which is so much more usefull.

The code is pretty straightforward on how it works, but reply to this post if you have any questions.

Good luck.

re: IIS Compression in IIS6.0

Barry — Tue, 01 May 2007 14:23:45 GMT

I've got an .aspx page that does the following:

It pulls a byte[] from a database, response.clear(), sets response.contenttype, response.binarywrite() to the browser, then a response.end(),

On IE 7, works great. On IE6, totally hosed.

Windows 2003 server, IIS 6. Compression on, it's broken, compression off, works every time.

PDF files work pretty consistenly, but .rtf, .tif, etc don't.

Any clues?

re: IIS Compression in IIS6.0

Jappenzeller — Fri, 30 Mar 2007 14:53:22 GMT

I can't seem to get the compression to work. I followed your directions exactly and I am out of ideas. I need help!

re: IIS Compression in IIS6.0

Carlos — Thu, 29 Mar 2007 20:04:56 GMT

Scott, thanks for the great article. I have one question, though: how should I proceed if I need to update any static files (css or js, for example)?

IIS Compression 'caches' them and their changes won't show up. How can I force IIS to update the compressed version? Does it have something to do with HcCacheControlHeader?

Thanks again for helping!

re: IIS Compression in IIS6.0

Steve — Mon, 26 Mar 2007 20:50:41 GMT

OWScott,

Hey I tried your mechanism, and it worked well.

I have a situation where I want a particular type of file to not be downloaded as a compressed file so I went to the IIS manager and made a change to the file just as you suggested.

Then I ran the ADSUTIL command as stated above to turn off dynamic compression for that one file. I was able to successfully download the files appropriately.

Thanks for the solution.

re: IIS Compression in IIS6.0

TechMate — Fri, 23 Feb 2007 18:04:40 GMT

With IIS 6.0 Compression enabled, can I use that for compressing .js and/or .css files?? I tried to add "js" to the HCFileExtensions and HCScriptFileExtensions in the Metabase file (separately and together), but I see the entries are removed after doing an IISReset... has anyone compressed javascript or Css files?? Is it even possible without third-party plugins??