A peek behind the scenes at Hotmail
Always wanted to know how hotmail is structured and how the architecture is looking. Here is your chance! Most interesting is to learn is how the non functionals are handled.
A small extract:
Hotmail is a gigantic service in all dimensions. Here are some of the highlights:
- We are a worldwide service, delivering localized versions of Hotmail to 59 regional markets, in 36 languages.
- We host well over 1.3 billion inboxes (some users have multiple inboxes)
- Over 350 million people are actively using Hotmail on a monthly basis (source: comScore, August 2009).
- We handle over 3 billion messages a day and filter out over 1 billion spam messages - mail that you never see in your inbox.
- We are growing storage at over 2 petabytes a month (a petabyte is ~1 million gigabytes or ~1000 terabytes).
- We currently have over 155 petabytes of storage deployed (70% of storage is taken up with attachments, typically photos).
- We’re the largest SQL Server 2008 deployment in the world (we monitor and manage many thousands of SQL servers).
You can imagine that the Hotmail user interface you see in the browser is only the tip of the iceberg – a lot of innovations happen beneath the surface. In this post I will give a high level overview of how the system is architected. We will do deeper dives into some specific features in later posts.