This was sent out to the App Engine Downtime Notify group:
We experienced an issue with Google App Engine Open ID service starting at 2013-10-24 13:40 US/Pacific. Some users got a 502 error when attempting to login to applications that use Open ID authentication. The problem was resolved as of 2013-10-24 15:15 US/Pacific. We apologize for the inconvenience and thank you for your patience and continued support. Please rest assured that system reliability is a top priority at Google, and we are making continuous improvements to make our systems better.
I had troubles with my regular Google account as well, but only on my Android phone. My first thought was to come on HN, but I did not see any news on it, so I thought it was me only - looks like I was wrong.
We experienced an issue with Google App Engine Open ID service starting at 2013-10-24 13:40 US/Pacific. Some users got a 502 error when attempting to login to applications that use Open ID authentication. The problem was resolved as of 2013-10-24 15:15 US/Pacific. We apologize for the inconvenience and thank you for your patience and continued support. Please rest assured that system reliability is a top priority at Google, and we are making continuous improvements to make our systems better.