Senior Database Administrator, Elan Technologies Inc. (Client: Well Med, A United Health Group company) Ph.D. Student, Computer and Information Sciences, University of Arkansas at Little Rock, Little Rock, Arkansas, United States
*Author correspondence: Mohsin A. Khan, Senior Database Administrator, Elan Technologies Inc. (Client: Well Med, a United Health Group company) Ph.D. Student, Computer and Information Sciences, University of Arkansas at Little Rock, Little Rock, Arkansas-United States, Email: mohsin7.dba@gmail.com
Online published on 25 August, 2021.
Disaster recovery (DR) is one of the most critical and often overlooked aspectsof database administration. A company may have an efficient database design, well-performing code, top-level security. However, it all comes to naught if there is no high availability and disaster recovery solution to meet the Service Level Agreement, Recovery Point Objective, and Recovery Time Objective in a time of disaster. Even if a company has a DR solution in place, more often than not, it is either misunderstood or not understood thoroughly, leading to uncertainty in determining the recovery time and availability for a database post disaster. In this article, the two primary SQL Server high availability and disaster recovery solutions are discussed, focusing on the events that trigger failovers, how failovers are handled, and the components that make up each of the two solutions with some illustrations.
SQL Server, Disaster recovery, High availability, Always On, Availability Groups, SQL failover cluster, Failover
