Question

I have a web service returning an XML value in a String format.

Through IE9, I can see that some of the size for the web service calls go as high as 1MB.

I enabled compression in IIS 6 by editing the Metabase.xml file, setting the following:

HcScriptFileExtensions = "asmx"

under the

IIsCompressionScheme    Location ="/LM/W3SVC/Filters/Compression/gzip"

I have also enabled HTTP Compression on the Service tab for the Web Sites properties in IIS Manager.

I have also added the HttCompression in the web service extensions, mapping to the gzip dll on the Windows\System32\inetsrv\ folder.

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).

Any tips to ensure that IIS compresses the string data value being returned by IIS?

Update:
I also followed the instructions on these links:

http://rextang.net/blogs/work/archive/2007/09/12/5654.aspx
http://blogs.msdn.com/b/rextang/archive/2007/09/13/4880187.aspx

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.

The web service SOAP XML (in String) value is still not being compressed. Any areas where I should be looking further?

By the way, I am using IIS6.

Update:
I checked this site:
http://blogs.iis.net/webtopics/archive/2009/02/24/troubleshooting-http-compression-in-iis-6-0.aspx

I got items 1,2,3 properly.

For item 4, I even tried only setting asmx as extension but to no avail.

For item 5, I don’t have any compression setting at a child level.

For item 6, the antivirus does not make a scan on the directory for compression.

For item 7, I am passing no slash as parameter on the executing DLL.

For item 8, I am unsure where/how to check for this.

For item 9, I have checked with fiddler and the proper headers are being placed on the request headers.

For item 10, I don’t see any settings in my apps that would require touching this.

For item 11, status code I am receiving is 200.

For item 12, the app is accessed with no proxy specified.

For item 13, the request is a web service.

Answer 1

Angelo,

The combination of settings on IIS6 are super sensitive and unforgiving. For example, the various configurable file extensions must each start on a new line – not delimited by spaces. The touchiness of IIS6’s compression is especially true where dynamically generated content (like returns from webservices) is involved.

Try the settings below, do an IIS Reset to reload these metabase changes, and cross your fingers!

<IIsCompressionScheme Location ="/LM/W3SVC/Filters/Compression/deflate"
    HcCompressionDll="%windir%\system32\inetsrv\gzip.dll"
    HcCreateFlags="0"
    HcDoDynamicCompression="TRUE"
    HcDoOnDemandCompression="TRUE"
    HcDoStaticCompression="TRUE"
    HcDynamicCompressionLevel="10"
    HcFileExtensions="htm
                      html
                      xml
                      css
                      txt
                      rdf
                      js"
    HcOnDemandCompLevel="10"
    HcPriority="1"
    HcScriptFileExtensions="asp
                            cgi
                            exe
                            dll
                            aspx
                            asmx"
        >
</IIsCompressionScheme>
<IIsCompressionScheme Location ="/LM/W3SVC/Filters/Compression/gzip"
    HcCompressionDll="%windir%\system32\inetsrv\gzip.dll"
    HcCreateFlags="1"
    HcDoDynamicCompression="TRUE"
    HcDoOnDemandCompression="TRUE"
    HcDoStaticCompression="TRUE"
    HcDynamicCompressionLevel="10"
    HcFileExtensions="htm
                      html
                      xml
                      css
                      txt
                      rdf
                      js"
    HcOnDemandCompLevel="10"
    HcPriority="1"
    HcScriptFileExtensions="asp
                            cgi
                            exe
                            dll
                            aspx
                            asmx"
        >
</IIsCompressionScheme>
<IIsCompressionSchemes Location ="/LM/W3SVC/Filters/Compression/Parameters"
    HcCacheControlHeader="max-age=86400"
    HcCompressionBufferSize="8192"
    HcCompressionDirectory="%windir%\IIS Temporary Compressed Files"
    HcDoDiskSpaceLimiting="FALSE"
    HcDoDynamicCompression="TRUE"
    HcDoOnDemandCompression="TRUE"
    HcDoStaticCompression="TRUE"
    HcExpiresHeader="Wed, 01 Jan 1997 12:00:00 GMT"
    HcFilesDeletedPerDiskFree="256"
    HcIoBufferSize="8192"
    HcMaxDiskSpaceUsage="99614720"
    HcMaxQueueLength="1000"
    HcMinFileSizeForComp="1"
    HcNoCompressionForHttp10="FALSE"
    HcNoCompressionForProxies="FALSE"
    HcNoCompressionForRange="FALSE"
    HcSendCacheHeaders="FALSE"
        >
</IIsCompressionSchemes>