Some sites hosted under the Cloud hosting service have been experiencing performance issues over the last two days. These issue have stemmed from load problems at our upstream provider Rackspace. More details can be found in this Rackspace status blog post.
In order to resolve these issues Rackspace engineers will be performing emergency maintenance today from 9pm – 10pm PST. During this timeframe some sites may be unavailable periodically. You can follow this blog post, and the Rackspace status blog above for more details as they become available.