I went to do my morning check of Digg.com, a social bookmarking site which despite the fact that it's mostly controlled by anti-Microsoft, Pro-Linux, and Pro-Apple people, is a fairly good way to keep up on tech news.
Alas, I was greeted with the message "We'll be back shortly". Digg was down. How annoying. I then saw that at the bottom of the page they link proudly to the various technologies they use to run Digg.com.
These include Debian Linux, Apache, PHP, and MySQL. A fairly classic LAMP implementation.
I found it quite ironic that they would brag about their awesome platform on a page that is displayed because they have downtime. If the platform was so awesome, why would they have downtime at all?
I know, I know, it all depends. It could be unavoidable downtime (like moving datacenters and not having enough redundancy to keep the site running), or downtime that won't cost as much as keeping the site running.
But I've become accustomed to 99.99%+ uptimes in my Windows 2003 Server / IIS 6 / ASP.NET / SQL Server 2000 applications. I typically use a combination of Network Load Balancing, SQL Server Clustering (on top of Windows Clustering Services), Microsoft Message Queuing, and a stateless application design to make it possible to have virtually no downtime whatsoever.
Doing production updates without any downtime can be a bit more tricky, but it's still entirely possible if you design your application right. IIS and ASP.NET have features built into it that allow for most updates to take place without a single request being lost.
For instance, if you're updating the binaries for an ASP.NET application, all requests that come in during that update are completed using the previous version of the application. As soon as the update is complete, requests will automatically be fulfilled with the new version of the application. And that's just one of many features.
While I'm sure that LAMP applications have solutions for these issues, as far as I know they're not built into the platform. If they were, maybe I would be reading Digg.com right now instead of writing this blog post. :)