GZIP Compression in IIS 7.5 is not working, How to trubleshoot? Please Help ....!

Question

User1919757445 posted

 Hi experts.

Here is my problem:

I'm trying to enable GZIP compression on IIS 7.5
bun no success after hours of googleing.

I think all the settings are ok

 In ApplicationHost.config I have this httpCompression section:

<httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files" minFileSizeForComp="0">
       <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" />
       </staticTypes>
</httpCompression>

And this urlCompression section:

<urlCompression dostaticcompression="true" />

 

and Here is Failed Request Tracing result:

STATIC_COMPRESSION_NOT_SUCCESS

Reason="UNKNOWN_ERROR"

 

Any help would be appreciated

Answer 1

User-176674611 posted

Hi,

I cannot followed your settings to reproduce your error. Would you please have a check which file extension of the request causes the error?

You can also refer to the following thread:
http://forums.iis.net/t/1071156.aspx
Hope this helps.

Thanks.

Answer 2

User1919757445 posted

Hi LIoydz. thanks for reply

For every extensions it fails to compress. I'm testing .js and .html files. but I know nothing is successfully compressed. I'm just trying to compress static types.

As I said, unfortunately in the "failed request trace" it shows Reason="UNKNOWN_ERROR"

In some forums and blogs people said maybe it's a matter of wrong permissions. some guy said IIS can not write in the "%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files"

I admit that nothing is written in that folder. but I dont know what is the user of IIS.

What is the best practice to set permissions. and how can I trace to find is it wrong permissions?

Answer 3

User-176674611 posted

Hi,

Please take the following steps to grant the write permissions:
Right click the folder -> Choose properties -> Select Security tab -> Click Edit -> Grant write permission to the user.

Please also check the following article to get detail information about Built-In User and Group Accounts in IIS 7.

Understanding Built-In User and Group Accounts in IIS 7
http://learn.iis.net/page.aspx/140/understanding-built-in-user-and-group-accounts-in-iis-7/

You can also use process monitor to trace which user intends to take write operation for the folder.

Thanks.

Answer 4

User1919757445 posted

Thanks  Lloydz

Problem solved.

It was permissions.

The article ( http://learn.iis.net/page.aspx/140/understanding-built-in-user-and-group-accounts-in-iis-7/)  is really good.

The problem was that IIS could not write it's gziped compressed files in the "IIS Temporary Compressed Files" folder.

I grant read/write permission to IIS_IUSRS for IIS Temporary Compressed Files folder. and it's now gziping...

The only thing is why a fresh installation of IIS had such misconfiguration !!!