PHP on Win: The whys and wherefores

BANGALORE, INDIA: Microsoft has always been known for its very tightly integrated pieces of software. For instance, if you look at components like ASP.NET, Active Directory, SQL Server, Exchange and SharePoint, all of these work extremely well together and provide a whole bunch of services to each other as well as a great development platform that lets you use and extend the features as you wish. However, one of the biggest complaints against Microsoft technologies was that they did not play fair with others' platforms.

The above complaint has been taken quite seriously by Microsoft and when developing the current version of Windows Server, they did a fairly surprising turn around. During the development phase for the latest version of Internet Information Services (IIS) 7.0, they collaborated with developers of PHP ? one of Microsoft's biggest rivals in the Web application platform space and what they both came up with is an interesting combination of features.

One of the big changes in IIS7 over previous version is the introduction of what is known as the ASP.NET Integrated Pipeline Mode. This mouthful actually means that development platforms that integrate into IIS7 (like PHP), gain access to many of the features of ASP.NET that are now ?exposed? as IIS features. This means that you can actually add a number of features into a PHP site on IIS7 very easily either using IIS management or an ASP.NET extension. Let's take a look at a couple of scenarios below to illustrate these points.

Let's say you have a large PHP site hosted on IIS7 using the Integrated Pipeline. You might find that performance of the site is not up to par and might want to go ahead and do something about it.

The very first thing that you might want to do is introduce caching into the web site so that repeated queries for the same page (or page signature - that includes queries to the database as well) are cached on the Web server and does not require a re-generation or round trip to the database. There are of course ways to achieve this in PHP itself either by writing your own (non-trivial) code or by including third party files or controls and configuring them.

However when working with IIS7, you can go ahead and use the IIS7's built in Output Caching mechanism that is based on the caching module feature of ASP.NET.

You can either use the IIS7 GUI or add a ASP.NET Web.config file with the relevant tags to your PHP site. In either case you can select different options for the cache, timeouts, change monitoring and expiration policy. With a couple of clicks you can enable your PHP site to get the comprehensive caching features of ASP.NET without a single line of code.

Let us take another scenario as well. Consider an enterprise PHP application that is important for your organization. Since your organization has grown since the time it was created, you might want to add or change the authorization and authentication mechanisms in this app. For instance, you might want to use a database or Active Directory to authenticate users and give different users access to different areas of the application based on some roles. Again, if you are running this on the LAMP stack, you will need to code in these changes yourself ? possibly in each page.

In IIS7, performing all of these tasks is simple and can be done without changing even a single line of code in your PHP application. Simply use the ASP.NET Membership and Roles modules as part of the IIS7 pipeline. For this, all you need to do is setup a connection string to the place where your users and roles are stored (database, ADS, etc.), setup a provider to point to these and then create a simple ASP.NET page with a Login control on it. You can also segregate different parts of the site to different users or roles by creating authorization entries through IIS.

The final example is of diagnosing problems in your web site. IIS7 contains a powerful tracing and diagnostics feature again taken from ASP.NET that is now available for PHP as well. You can quickly perform traces on your web site and get detailed diagnostic information regarding performance and failures and use these to troubleshoot your site.

IIS7 comes with more than 40 such features built in. You can also download a whole bunch of more modules (such as ad management, stop hot linking, URL rewriting, media streaming and many many more) from the Internet or write your own using the SDK. Getting access to the extremely rich and powerful feature set of ASP.NET without having to recode your own PHP pages is also a great benefit that clearly puts the advantages of using PHP on Windows 2008 in front.

We'll continue this series with some other explorations ? such as benchmarks of PHP applications running on different platforms as well as a look at the TCO of these cases.