Getting Started: DBA Core Tasks

Recently i read through feed from Windows Blog which talk about Hotmail from Arthur de Haan (Director, Windows Live Test and System Engineering) who responsible on Test and System Engineering in Window Live. who explain what it takes to build, deploy and run Windows Live Hotmail services on global scale.

As what he mention hosting mail and data (and also their own data!!) on their servers is a big responsibility and he take quality. performance , and reliability very seriously. Microsoft have make significant investment in engineering and infra to help keep hotmail up and running 24 hours a day , day in and day out , year after year. Although we something complaint on thing which goes wrong but we don’t know how many effort is putting on the backend.

Some highlights on his post are

• 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).

  SQL Server 2008 in live production for Micrsoft Live ???? I believe only Microsoft dare to put new version on production but not other company can do this. Even with customer my company support we don’t really implement latest database version except if special request by customer and also the hosting and infra tools must be able to support as well.

I will like to focus on this

Here are a few of the ways we keep failures contained:

• Redundancy – We use a combination of SQL server storage arrays to host our data. We use active/passive failover technologies. This is a fancy way of saying that we have multiple servers and copies of your data that are constantly synchronized. If one server has a failure, another one is ready to take over in seconds. All in all we keep four copies of your data on multiple drives and servers to minimize the chance of data loss due to a hardware failure. Another benefit of this architecture is that we can perform planned maintenance (such as deploying code updates or security patches) without downtime for you. Key pieces of our network gear are also duplicated to minimize the chance of network-related outages.
• Monitoring – We have an elaborate system for monitoring hardware and software. Thousands of servers monitor service health, transactions (for example, sending an e-mail) and system performance for customers all over the world. Because we’re so large, we’re tracking performance and uptime metrics in aggregate as well as at the cluster level, and by geography. We do want to make sure that your individual experiences are reflected back to us, and not getting lost when we look at averages for the entire system. We care about every single user’s experience. We’ll talk more about performance and monitoring in a future post.
• Response center – We have a round-the-clock response center team that watches over our global monitoring systems and takes action immediately when there is problem. We have an escalation process that can engage our engineering staff within a few minutes when needed —Again from India i believe

Overall we can see that even with a Free services , Microsoft is taking serious on maintain their delivery and deploy new technology into the Free business used. We should be thankful for this .

at the same time i can see that Microsoft is using MS Live Hotmail as beta-land for their new SQL Server 2008 . I wonder how is the technology deploy behind this…it must be a gigantic system.

Full copy of the article can be read from this http://windowsteamblog.com/blogs/windowslive/archive/2009/12/22/a-peek-behind-the-scenes-at-hotmail.aspx