The ICPSR web site and the CCEERC web site were unavailable from 4:27am EDT until 5:04am EDT on Sunday, June 28, 2009. This was an unscheduled outage.
The proximate reason for outage was that the DNS software on the ICPSR DNS server faulted at 4:24am EDT, and stopped answering queries. This had the unexpected side-effect of reducing the response time on the ICPSR and CCEERC web sites to the point where the sites stopped serving requests.
ICPSR IT staff were paged at 4:25am EDT, and began diagnosing the situation shortly thereafter. By 5:00am EDT it was clear that the root problem was not with the web server itself, and staff isolated the problem to the DNS server at that time.
Our apologies for any inconvenience this may have caused.