Is it worth it to enable dynamic compression in IIS7

asp.netcompressioniis-7

I am trying to find all possible ways I could improve my website performance. I was considering enabling dynamic compression at the server level but was concerned by performance hits (no caching of compressed pages – corruption of files – overhead on the server).
Should I just give up on the dynamic compression with IIS 7? are there modules out there that do a better job than the built-in compression module?

Best Answer

You should almost always enable dynamic compression (static is on by default). Dynamic compression == undue processing stress is a pernicious myth. Here's MSDN:

Despite a common myth, dynamic compression usually does not have a prohibitive CPU overhead. In fact, dynamic compression often causes less than 5 percent of the total CPU utilization on a busy server. Dynamic compression can be deployed somewhat liberally to allow for maximum bandwidth savings for any application workloads.

Also, you can specify a CPU throttle for compression in IIS7.

Configuration

You can enable GZIP compression entirely in your Web.config file. This is particularly useful if you're on shared hosting and can't configure IIS directly, or you want your config to carry between all environments you target.

<system.webServer>
  <httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files">
    <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll"/>
    <dynamicTypes>
      <add mimeType="text/*" enabled="true"/>
      <add mimeType="message/*" enabled="true"/>
      <add mimeType="application/javascript" enabled="true"/>
      <add mimeType="*/*" enabled="false"/>
    </dynamicTypes>
    <staticTypes>
      <add mimeType="text/*" enabled="true"/>
      <add mimeType="message/*" enabled="true"/>
      <add mimeType="application/javascript" enabled="true"/>
      <add mimeType="*/*" enabled="false"/>
    </staticTypes>
  </httpCompression>
  <urlCompression doStaticCompression="true" doDynamicCompression="true"/>
</system.webServer>

Testing

To test whether compression is working or not, use the developer tools in Chrome or Firebug for Firefox and ensure the HTTP response header is set:

Content-Encoding: gzip

Note that this header won't be present if the response code is 304 (Not Modified). If that's the case, do a full refresh (hold shift or control while you press the refresh button) and check again.

Asp.net-mvc – the difference between ‘classic’ and ‘integrated’ pipeline mode in IIS7

Classic mode (the only mode in IIS6 and below) is a mode where IIS only works with ISAPI extensions and ISAPI filters directly. In fact, in this mode, ASP.NET is just an ISAPI extension (aspnet_isapi.dll) and an ISAPI filter (aspnet_filter.dll). IIS just treats ASP.NET as an external plugin implemented in ISAPI and works with it like a black box (and only when it's needs to give out the request to ASP.NET). In this mode, ASP.NET is not much different from PHP or other technologies for IIS.

Integrated mode, on the other hand, is a new mode in IIS7 where IIS pipeline is tightly integrated (i.e. is just the same) as ASP.NET request pipeline. ASP.NET can see every request it wants to and manipulate things along the way. ASP.NET is no longer treated as an external plugin. It's completely blended and integrated in IIS. In this mode, ASP.NET HttpModules basically have nearly as much power as an ISAPI filter would have had and ASP.NET HttpHandlers can have nearly equivalent capability as an ISAPI extension could have. In this mode, ASP.NET is basically a part of IIS.

Best Answer

Related Solutions

Enable IIS7 gzip

Configuration

Testing

Asp.net-mvc – the difference between ‘classic’ and ‘integrated’ pipeline mode in IIS7

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