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tugberk
Asked: 2011-08-06 10:09:34 +0800 CST

GZip Compression On IIS 7.5 is not working

  • 772

I am trying to support GZip compression for my static files under IIS (which should be enabled by default but not) but not working so far. Here is the the section under <system.webServer> node inside the web.config file of the web app;

<httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files">
  <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll" staticCompressionLevel="9" />
  <dynamicTypes>
    <add mimeType="text/*" enabled="true" />
    <add mimeType="message/*" enabled="true" />
    <add mimeType="application/x-javascript" enabled="true" />
    <add mimeType="application/json" enabled="true" />
    <add mimeType="*/*" enabled="false" />
  </dynamicTypes>
  <staticTypes>
    <add mimeType="text/*" enabled="true" />
    <add mimeType="message/*" enabled="true" />
    <add mimeType="application/x-javascript" enabled="true" />
    <add mimeType="application/atom+xml" enabled="true" />
    <add mimeType="application/xaml+xml" enabled="true" />
    <add mimeType="*/*" enabled="false" />
  </staticTypes>
</httpCompression>

<urlCompression doStaticCompression="true" />

I tried it with Google Chrome. Here are the Request Headers;

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8

Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3

Accept-Encoding:gzip,deflate,sdch

Accept-Language:en-US,en;q=0.8

Cache-Control:no-cache

Connection:keep-alive

Host:my-website-url

Pragma:no-cache

User-Agent:Mozilla/5.0 (Windows NT 6.0) AppleWebKit/534.30 (KHTML, like Gecko) Chrome/12.0.742.122 Safari/534.30

These are the Response Headers;

Accept-Ranges:bytes

Content-Length:232651

Content-Type:application/x-javascript

Date:Thu, 04 Aug 2011 08:58:19 GMT

ETag:"a69135734a50cc1:0"

Last-Modified:Mon, 01 Aug 2011 12:56:37 GMT

Server:Microsoft-IIS/7.5

X-Powered-By:ASP.NET

I check the applicationHost.config file and found some nodes like below;

----

<section name="httpCompression" allowDefinition="AppHostOnly" overrideModeDefault="Deny" />

----

<section name="urlCompression" overrideModeDefault="Allow" />

----

<httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files">
    <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll" />
    <staticTypes>
        <add mimeType="text/*" enabled="true" />
        <add mimeType="message/*" enabled="true" />
        <add mimeType="application/x-javascript" enabled="true" />
        <add mimeType="application/atom+xml" enabled="true" />
        <add mimeType="application/xaml+xml" enabled="true" />
        <add mimeType="*/*" enabled="false" />
    </staticTypes>
</httpCompression>

----

<urlCompression />

What am I missing here?

windows-server-2008 iis iis-7.5 .net windows-server-2008-r2

3 Answers

  1. It appears you may not have permissions set correctly on the temp compression folder. You ned to ensure the user your IIS install (or application) is running as has write permission to the compression folder.

    More here

    • 3

  2. After a lot of searching, I finally found what got compression working on my IIS 7.5. To start with, IIS will not compress a file unless it loaded often enough. That brings up the question "what does IIS consider often enough?" Well, the defaults are 2 times every 10 seconds. Yikes!

    This setting can be changed in web.config, but the section needs to be unlocked first in applicationHost.config. Here are the commands:

    First unlock the section:

    C:\Windows\System32\inetsrv\appcmd.exe unlock config /section:system.webServer/serverRuntime

    Unlocked section "system.webServer/serverRuntime" at configuration path "MACHINE/WEBROOT/APPHOST".

    Now that is done, edit the web.config file and add the serverRuntime element:

    <?xml version="1.0" encoding="UTF-8"?> <configuration>
    <system.webServer>
        <serverRuntime frequentHitThreshold="1" frequentHitTimePeriod="10:00:00" />
        ...

    In this case, I set it to hit the file once in a 10 hour period. You can adjust the values as necessary. Here is the document that explains the serverRuntime element:

    http://www.iis.net/configreference/system.webserver/serverruntime

    I hope this helps get your compression working as well.

    Note: you can also set the serverRuntime element up in the applicationHost.config file, but I chose to change it in the web.config because we have a number of servers and farms with various sites, and it is easier for me to control it from this level of granularity.

    • 1

  3. This is working for me:

     <urlCompression doStaticCompression="true" doDynamicCompression="true" dynamicCompressionBeforeCache="true" />
<httpCompression noCompressionForRange="false" noCompressionForHttp10="false" noCompressionForProxies="false">
  <dynamicTypes>
    <add mimeType="text/css" enabled="true" />
  </dynamicTypes>
  <staticTypes>
    <add mimeType="text/css" enabled="true" />
  </staticTypes>
 <staticTypes>
    <add mimeType="text/javascript" enabled="true" />
  </staticTypes>
</httpCompression>

    There is also text/javascript mime-type, and you only have application one. It was an issue until I included text/...

    • -1