The issue with Google App Engine services has been resolved for all affected projects as of 21:00 US/Pacific. We will conduct an internal investigation of this issue and make appropriate improvements to our systems to help prevent or minimize future recurrence.

[Google Cloud Platform Status]

On Wednesday 31 January 2017, some Google Cloud services experienced
elevated errors and latency on operations that required inter-data center
network traffic for a duration of 72 minutes. The impact was visible during
three windows: between 18:20 and 19:08 PST, between 19:10 and 19:29, and
again between 19:45 and 19:50. Network traffic between the public internet
and Google's data centers was not affected by this incident.

The root cause of this incident was an error in a configuration update to
the system that allocates network capacity for traffic between Google data
centers.

To prevent a recurrence, we will improve the automated checks that we run
on configuration changes to detect problems before release. We will be
improving the monitoring of the canary to detect problems before global
rollout of changes to the configuration.