httpCompression dynamicTypes not matching the wildcard *(star) in “application/json*” RRS feed

  • Question

  • User1192863210 posted

    The Problem:

    My goal is to enable gzip compression of responses from IIS for the content-type "application/json*", but when the wildcard * is added instead of an exact string match compression fails.

    Enabling the FailedRequestLogs and making a request to IIS for which the response is:

    HTTP/1.1 200 OK
    Cache-Control: private
    Content-Length: 41
    Content-Type: application/json; charset=utf-8

    The Result is:

    My configuration & Results:

    When "C:\Windows\System32\inetsrv\config\applicationHost.config" is configured with:

    <httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files" noCompressionForHttp10="false" noCompressionForProxies="false">
      <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll" />
          <add mimeType="application/json*" enabled="true" />
          <add mimeType="*/*" enabled="false" />
          <add mimeType="application/json*" enabled="true" />
          <add mimeType="*/*" enabled="false" />

    The "application/json*" wildcard matching fails.

    But when configured with:

    <add mimeType="application/*" enabled="true" /> 

    The wildcard is evaluated and works correctly.

    Additionally, when configured with:

    <add mimeType="application/json" enabled="true" /> 
    <add mimeType="application/json; charset=utf-8" enabled="true" /> 

    The exact string matching also works.

    In further testing, I found that the wildcard only seems to work immediately following the '/' in the mimeType. (ex: "abc/*")

    The Question is, why doesn't wildcard matching work when there are characters after the '/' like in "application/json*"?

    Friday, January 29, 2016 12:33 PM

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