Here are some links for the research areas as outlined for Hadoop:

http://wiki.apache.org/hadoop/ProjectSuggestions

• Hadoop Security Design: A design is part of the Hadoop-4487. Check it out here: https://issues.apache.org/jira/browse/HADOOP-4487
• Replication: I am wondering how we can apply of our work on Optimistic Replication be used with Hadoop.
• Virtualization: Use virtualization to improve the performance and stability of Hadoop upon failures.

I need to look deeply in the design of Hadoop to start working on some of these projects.