The book provides case studies of numerous existing compute, storage, and application cloud services and illustrates capabilities and limitations of current providers of cloud computing services. This allows the reader to understand the mechanisms needed to harness cloud computing in their own respective endeavors. Finally, many open research problems that have arisen from the rapid uptake of cloud computing are detailed. This book contains chapters authored by several leading experts in the field of cloud computing. The book is presented in a coordinated and integrated manner starting with the fundamentals and followed by the technologies that implement them. The content of the book is Introduction and Brief History of cloud computing, Cloud computing security issues, General security issues, What to migrate, Cloud interoperability issues, Secure Query processing with HADOOP, HADOOP how it manages security, Cloud computing Challenges.