This is not an official Valve post mortem, rather an analysis by the company Thousand Eyes who make network troubleshooting tools.
Data centers are the factories of the Internet, churning out computation and services that customers demand. Apple is currently converting a 1.3M sq ft factory into a data center. And like factories, data centers rely on critical services to stay running. In the case of a data center, the most important inputs are electricity, cooling and network connectivity. Typically, redundant supplies of each input are available should there be a problem. Let’s examine an outage that occurred yesterday to see the importance of monitoring data center ingress, or network connectivity into the data center.