We've deployed a run-time fix which should result in all apt-get actions using "us.archive.ubuntu.com" and are monitoring things closely.
Posted Mar 08, 2016 - 22:32 UTC
Identified
The primary Ubuntu mirror for the GCE region we use in GCE is currently showing very slow download speeds. We've reached out to the mirror administrators and are working with them on getting this resolved. We are also looking into a run time fix for this in the mean time.