Google Big Data Reference

Hadoop DFS :
http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en//archive/gfs-sosp2003.pdf

Hadoop MapReduce :
http://static.usenix.org/event/osdi04/tech/full_papers/dean/dean.pdf

HBase, Cassandra .. :
http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en//archive/bigtable-osdi06.pdf

Hive, Pig :
http://research.google.com/archive/sawzall.html

Apache ZooKeeper :
http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en//archive/chubby-osdi06.pdf