On Monday, many of the millions of Gmail users could not access their accounts for close to an hour in the early afternoon (Eastern Time). Other services operated by Google also experienced issues at around the same time which included its Chrome web browser, which crashed a number of times for many of its users on Monday.
So what happened? According to a forum post by Google engineer Tim Steele on the Chromium.org site, the problems with Gmail, Chrome and other Google services were all caused by an issue with Google Sync. He stated that the server's infrastructure has a feature that enforces "quotas on per-datatype sync traffic."
That quota service experienced traffic problems today due to a faulty load balancing configuration change. That change was to a core piece of infrastructure that many services at Google depend on. This means other services may have been affected at the same time, leading to the confounding original title of this bug.
The servers, in turn, "reacted too conservatively", according to Steele and that caused the server's clients to throttle all of the data types. The problem is Chrome doesn't actually support all those data types, which caused the web browser to crash for many users. Google corrected the issue quickly but the downtime was long enough to expose how critical Google's infrastructure is to our daily operations.
Source: Chromium.org | Image via Google