Today at 20:00 UTC we saw a traffic surge on our load balancing and caching infrastructure, resulting in intermittent outages in Wikipedia service worldwide. This was due to a complex interaction of factors, including issues in our Amsterdam caching center and the Fundraiser launch, which has generated much more than expected interest today. We switched all traffic to Tampa, which experienced service problems due to high traffic and the additional load. Currently service is fully recovered worldwide, and we are continuing to closely monitor all systems.

Danese Cooper
CTO, Wikimedia Foundation