1 research outputs found
Database High Availability As A Service For Cloud Computing
Title from PDF of title page, viewed on August 23, 2016Dissertation advisor: Vijay KumarVitaIncludes bibliographical references (pages 115-122)Thesis (Ph.D.)--School of Computing and Engineering. University of Missouri--Kansas City, 2016On 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
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 – DataBase 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 clOud 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.Introduction -- Literature review -- DBHAaaS - AAP -- Identification of Geolocation of Cloud Datacenter -- Conclusion and future wor