Looks like a bad change was propagated to the mirrors or something, all of them are 404'ing for /apache/hadoop/common and the only thing in /apache/hadoop on any mirror is "Chukwa"
http://www.apache.org/dyn/closer.cgi/hadoop/common/ IE: http://mirrors.koehn.com/apache/hadoop/common/ http://mirrors.koehn.com/apache/hadoop/ -- Iain Wright
