DBHAAAS – DATABASE HIGH AVAILABILITY AS A SERVICE FOR CLOUD COMPUTING A DISSERTATION IN Computer Science and Telecommunications and Computer Networking Presented to the Faculty of the University of Missouri-Kansas City in partial fulfillment of the requirements for the degree DOCTOR OF PHILOSOPHY by CHETAN JAISWAL B.E., Rajiv Gandhi Technical University, 2007 Kansas City, Missouri 2016 © 2016 CHETAN JAISWAL ALL RIGHTS RESERVED DBHAAAS – DATABASE HIGH AVAILABILITY AS A SERVICE FOR CLOUD COMPUTING Chetan Jaiswal, Candidate for the Doctor of Philosophy Degree University of Missouri-Kansas City, 2016 ABSTRACT On conventional database systems, the recovery manager applies transaction Undo or Redo operation or a combination of them to recover the last consistent state of the database from a system failure. Transaction redo, compared to undo, helps to shorten the system downtime so the execution of transactions is managed in such a way that majority of transactions require redo to recover the database. To further reduce the recovery time, the recovery module uses “Checkpoint” operation. Even though it is possible to eliminate transaction redo altogether, the conventional system architecture, however, is not capable to deploy innovative approaches. The availability of “Virtual” machines on cloud has given us an architecture that makes it possible to completely do away with transaction redo which allows us to eliminate the effect of system or transaction failure by taking the database to the next consistent state. In this dissertation, we present a novel scheme of eliminating the effect of such failures by applying transaction “roll-forward.” Our approach intelligently applies roll-forward from the iii point of failure which removes the effect of system failure on the database. We refer to our system as AAP ( Always Ahead Processing). In AAP a transaction always executes to completion. We have made forward execution of transactions persistent by combining together transaction execution, transaction failure and its subsequent recovery as one seamless operation. Unlike legacy recovery scheme, in our approach transactions roll forward from the point of failure while concurrently executing other transactions. As a result, system downtime during recovery is eliminated. The end result is a database system with high availability and fault-tolerance. Our work enables cloud providers to offer transactional HA-DBMS (Highly Available – Data Base Management System) as an option that too with multiple data sources not necessarily only relational. AAP is independent of the underlying cloud architecture and therefore can be used in different type of cloud settings like public, private, hybrid or federated. In a federated cloud, the location of the physical host machine(s) is very important for fast and responsive HA ( High Availability) service. We designed and developed a tool that will aid AAP to find the nearest physical host. We call this tool IGOD (Identification of Geolocation of cl Oud Datacenter). Apart from aiding AAP in a federated cloud, IGOD is an independent tool and can also be used for enforcing privacy and security in cloud datacenters; in particular for HIPAA compliant data storage. Our prototype demonstrates AAP’s HA, fault tolerance and the elimination of system downtime during recovery from a failure. iv APPROVAL PAGE The faculty listed below, appointed by the Dean of the School of Graduate Studies, have examined a dissertation titled ”DBHAAAS – Database High Availability As A Service For Cloud Computing,” presented by Chetan Jaiswal, candidate for the Doctor of Philosophy degree, and certify that in their opinion it is worthy of acceptance. Supervisory Committee Vijay Kumar, Ph.D., Committee Chair Department of Computer Science Electrical Engineering Yugyung Lee, Ph.D. Department of Computer Science Electrical Engineering Praveen R. Rao, Ph.D. Department of Computer Science Electrical Engineering Cory Beard, Ph.D. Department of Computer Science Electrical Engineering Lein Harn, Ph.D. Department of Computer Science Electrical Engineering v CONTENTS ABSTRACT ................................................................................................................................. iii LIST OF ILLUSTRATIONS ...................................................................................................... viii LIST OF TABLES ........................................................................................................................ xi ACKNOWLEDGEMENTS ......................................................................................................... xii Chapter 1. INTRODUCTION .............................................................................................................. 1 1.1 Our Idea .........................................................................................................................5 1.2 Our Contributions ........................................................................................................13 1.3 Organization .................................................................................................................14 2. LITERATURE REVIEW ..................................................................................................15 3. DBHAaaS – AAP ..............................................................................................................26 3.1 Current Transaction Processing Scenario ....................................................................27 3.2 Unbundled Transaction Processing..............................................................................30 3.3 Architecture..................................................................................................................31 3.4 State Replication ..........................................................................................................33 3.5 Pulse and Failover ........................................................................................................36 3.6 Transaction Log ...........................................................................................................39 3.7 Concurrency Control ....................................................................................................43 3.8 Evaluation ....................................................................................................................44 vi 4. Identification of Geolocation of Cloud Datacenter ............................................................69 4.1 Location Requirement: AAP in a Federated Cloud .....................................................69 4.2 Privacy and Trust .........................................................................................................71 4.3 Proportionality between Delay and Distance ...............................................................73 4.4 IGOD Algorithm ..........................................................................................................80 4.5 Prototype Implementation of IGOD ............................................................................84 4.6 Evaluation ....................................................................................................................93 4.6.1 Dataset Impact ...................................................................................................93 4.6.2 Geolocating Emulated DC ................................................................................100 4.6.3 Geolocating Amazon S3 DC .............................................................................103 4.6.4 Observation .......................................................................................................106 4.6.5 Discussion .........................................................................................................109 5. CONCLUSION AND FUTURE WORK ........................................................................112 REFERENCES ............................................................................................................................115 VITA ............................................................................................................................................123 vii ILLUSTRATIONS Figure Page 1. Undo Operation ....................................................................................................................7 2. Redo Operation ....................................................................................................................7 3. Failure and Resumption .......................................................................................................8 4. ULT ....................................................................................................................................28 5. Server Classes ....................................................................................................................29 6. AAP Failover and Architecture .........................................................................................32 7. Transaction Instances .........................................................................................................35 8. Communication Protocol ...................................................................................................38 9. Log Structure .....................................................................................................................41 10. Log Servers’ Cluster ..........................................................................................................41