tailieunhanh - On Designing and Deploying Internet-Scale Services

The system-to-administrator ratio is commonly used as a rough metric to understand administrative costs in high-scale services. With smaller, less automated services this ratio can be as low as 2:1, whereas on industry leading, highly automated services, we’ve seen ratios as high as 2,500:1. Within Microsoft services, Autopilot [1] is often cited as the magic behind the success of the Windows Live Search team in achieving high system-to-administrator ratios. While auto-administration is important, the most important factor is actually the service itself. Is the service efficient to automate? Is it what we refer to more generally as operations-friendly? Services that are operationsfriendly require little human intervention, and. | On Designing and Deploying Internet-Scale Services James Hamilton - Windows Live Services Platform ABSTRACT The system-to-administrator ratio is commonly used as a rough metric to understand administrative costs in high-scale services. With smaller less automated services this ratio can be as low as 2 1 whereas on industry leading highly automated services we ve seen ratios as high as 2 500 1. Within Microsoft services Autopilot 1 is often cited as the magic behind the success of the Windows Live Search team in achieving high system-to-administrator ratios. While auto-administration is important the most important factor is actually the service itself. Is the service efficient to automate Is it what we refer to more generally as operations-friendly Services that are operations-friendly require little human intervention and both detect and recover from all but the most obscure failures without administrative intervention. This paper summarizes the best practices accumulated over many years in scaling some of the largest services at MSN and Windows Live. Introduction This paper summarizes a set of best practices for designing and developing operations-friendly services. Designing and deploying high-scale services is a rapidly evolving subject area and consequently any list of best practices will likely grow and morph over time. Our aim is to help others 1. deliver operations-friendly services quickly and 2. avoid the early morning phone calls and meetings with unhappy customers that non-opera-tions-friendly services tend to yield. The work draws on our experiences over the last 20 years in high-scale data-centric software systems and internet-scale services most recently from leading the Exchange Hosted Services team at the time a midsized service of roughly 700 servers and just over users . We also incorporate the experiences of the Windows Live Search Windows Live Mail Exchange Hosted Services Live Communications Server Windows Live Address Book Clearing House