One of the products that my team builds that I am most proud of is IIS 7. IIS 7 is a *major* update of our web-server stack, and introduces a significantly new and improved extensibility, configuration, and administration architecture. I've blogged about some of its features in the past here and here.
Doing a major re-architecture on a mature product is never easy. Doing so on one that runs more than 40% of the web servers on the Internet is especially daunting. The final product, though, is fantastic - and delivers an incredibly flexible, scalable, and robust server architecture that is going to enable us to-do really exciting things going forward.
Earlier this week we shipped the RC0 build of Windows Server 2008 and IIS 7.0. You can learn more about it and download the RC0 version from Mai-lan's blog post here.
IIS 7.0 Extensibility (and why it is cool)
One of the major changes we made to IIS 7.0 was to make the system radically more extensible than previous versions of the web-server. This extensibility applies both to the core HTTP processing engine, as well as to the configuration system, health monitoring system, and admin tool architecture. You can now write managed .NET classes to cleanly extend all of these sub-systems.
This is great from a customer perspective (since you can now replace and extend anything in the system). It also enables us to easily ship web-server extensions and additions in a very agile way on the web. Starting this week you are going to begin to see a number of really cool, fully-supported, free features start to be delivered this way. Below are a few of them available this week:
IIS 7.0 FTP Publishing Service
We are delivering a new modern FTP service implementation that runs on IIS 7.0. This FTP service offers a much improved administration and configuration experience (it uses the same web.config model as IIS7 and ASP.NET, and integrates into the IIS7 admin tool). It now supports FTP over SSL, as well as UTF8 and IPv6.
The FTP server enables you to host both FTP and web content from the same web-site on IIS7 (just add a FTP binding to your existing web-site to enable it). It now provides support for virtual host names, which means you can host multiple FTP sites on the same IP address. It also has built-in user-isolation support, which makes it perfect for shared hosting scenarios.
The FTP server's authentication system is now pluggable - which means you can add your own username/password store to manage logins. Best of all, you can use the existing ASP.NET Membership Provider model to plug-in your own credential system for logins and user management.
IIS 7.0 Media Pack Bit-Rate Throttling Module
One of the challenges when hosting large videos and audio files on the Internet is that bandwidth costs can be expensive. What is worse is that you often end up having to pay for users to download videos that aren't fully watched. Specifically, web-servers are by default designed to download content files as fast as possible. So if a user visits your site and starts watching a 50MB video on it, the web-server will by default try and transmit the 50MB file as quickly as possible to them. If the user closes the browser half-way through watching the video, you will end up having to pay for the remaining 25MB of content they had finished downloading - but which they never actually watched.
The IIS 7.0 Media Pack Bit-Rate throttler provides a much more cost-effective way to host video and audio on standard web-servers. When a browser (using a plug-in like Silverlight, Flash, Windows Media Player, iTunes, etc) requests a media file, IIS7 will automatically detect the encoding bit-rate of the file and determine how many bytes per second the player needs to receive to play it continuously.
IIS7 will then "burst" enough of the content (by default 20 seconds of the video/audio file) to ensure that the client player can start playing the video, and won't ever run into a buffering delay. IIS7 then automatically slows down the file transmission to equal the encoded bit-rate (so if the video is encoded at 400kbs, IIS7 will burst 20 seconds of this, and then slow the remaining transmission to 400kbs of content). If the user closes the browser on the video while it is playing, IIS7 will automatically detect the connection was dropped and avoid sending any more of the content (saving you the remaining bandwidth costs). This module works today with Silverlight, Flash and Windows Media Player - no code changes are required in the players to enable it.
IIS 7.0 Remote Manager Administration Tool
IIS 7.0 ships with a significantly improved administration tool experience. The admin tool is entirely written in managed code (using Windows Forms), and supports remotely administering a web-server over HTTP based web-services (allowing you to use the admin tool to manage servers remotely in a hosted environment through proxy servers). The administration tool supports configuring both standard IIS settings, as well as ASP.NET ones (for example: you can use the tool to remotely manage ASP.NET membership/roles).
Earlier this week we shipped a standalone installation of the IIS 7.0 admin tool that you can use to remotely manage Windows Server 2008 based IIS7 web-servers from Windows XP, Windows Server 2003, and Windows Vista client machines.
FastCGI Support for IIS 5.1 and IIS 6.0
IIS 7.0 ships with built-in support for FastCGI - which is a high performance alternative to using CGI for web-server extensibility. Many popular web frameworks (in particular PHP) use this to integrate with web-servers. In addition to having FastCGI support built-in to IIS 7.0, this week we also shipped a FastCGI ISAPI extension that works on existing IIS 5.1 and IIS 6.0 web servers.
The extensibility architecture of IIS7 is going to enable us to continually enhance and ship more features that run on top of it in the months ahead. I'll be blogging more soon about some of these additional extensions (including about a new new wickedly cool automated web deployment system that supports rolling out versioned web applications across servers - including to remote web servers, and across web-server farms).
Hope this helps,