High Availability for Database Systems in Cloud Computing Environments

November 15, 2011
Ashraf Aboulnaga | University of Waterloo

Maintaining availability in the face of hardware failures is an important goal for any database system. Users have come to expect 24×7 availability even for simple non-critical applications, and businesses can suffer costly and embarrassing disruptions when hardware fails. Many database systems are designed to continue serving user requests with little or no disruption even when hardware fails. However, this high availability comes at a high cost in terms of complex code in the database system, complex setup for the database administrator, and sometimes extra specialized hardware. In this talk, I will discuss approaches for providing high availability for database systems by taking advantage of the capabilities of cloud computing technologies. I will describe RemusDB, a system for providing active/stand-by replication for high availability based on full virtual machine state replication. I will also describe DBECS, a scalable, highly available, multi-tenant database service that is built on the Cassandra eventually consistent cloud storage system. DBECS carefully exploits the semantics of database transactions to provide strong transactional guarantees on top of the eventually consistent Cassandra, while retaining Cassandra’s good scalability, low write latency, and partition tolerance, which we exploit for high availability. The goal of both of these projects is to take the complexity of high availability out of the database system, and let the cloud infrastructure below the DBMS provide high availability as a service.

Speaker Details

Ashraf Aboulnaga is an Associate Professor in the Cheriton School of Computer Science at the University of Waterloo, Canada. His research interests are in the area of database management, with a current focus on cloud computing, data integration on the web, self-managing database systems, and XML databases.

Dr. Aboulnaga obtained M.S. and Ph.D. degrees from the University of Wisconsin – Madison and B.S. and M.S. degrees from Alexandria University, Egypt. He was a Research Staff Member at the IBM Almaden Research Centre from 2002 to 2004, and a Visiting Research Scientist at Google Waterloo during his sabbatical in 2009-2010. Dr. Aboulnaga is an IBM Centre for Advanced Studies Faculty Fellow and a recipient of a Google Research Award, the Ontario Early Researcher Award, and a Best Paper Award at VLDB 2012. He is a senior member of the IEEE and ACM, and serves on the technical advisory board of ClevrU Corp.