Introduction

A True Story Los Angeles, California, December 10, 2012, 9:00 AM. John has just arrived at his office and is trying to access his email but experiences many problems. The performance is slow, timeouts expire, and he receives a number of “Server Error 502" messages. He is wondering whether the problem is with his client, with the network connection, or with the server. He cannot know that thousands of other users are experiencing similar problems-not only with emails but also with other services from the same provider.