Measuring end-user availability on the Web: practical experience

For service applications on a network, measuring availability, performance, and quality of service is critical. Yet traditional software and hardware measures are both inadequate and misleading. Better measures of availability that incorporate end-user experience will lead to meaningful benchmarks and progress in providing high availability services. We present the results of a series of long-term experiments that measured availability of select Web sites and services with the goal of duplicating the end-user experience. Using our measurements, we propose a new metric for availability that goes beyond the traditional sole measure of uptime.