A fire destroys the primary data center. The order database has an asynchronously replicated secondary in another region that is a few seconds behind. The applications connect through a DNS name that points to the primary. What should the DBA do to restore service?
Select an answer to reveal the explanation.
Short Explanation
Failover is passing the baton: the secondary has to take the lead and everybody has to start running toward it. You promote the replica, point the DNS name or connection strings at it, and check that the apps can write. Promoting it without moving the traffic is like crowning a new captain no one can find.
Full Explanation
Failover is the process of switching operations from a failed primary to a standby. With the primary site destroyed, the DBA promotes the asynchronous secondary to a writable primary, accepting the few seconds of transactions that had not replicated, and then redirects clients by updating the DNS record, listener or connection strings so applications reach the new primary. Verification follows: confirm the applications connect and write successfully, check data for the most recent transactions, and confirm backups now run against the new primary. Waiting for the primary site to be rebuilt ignores the standby that exists precisely for this event and leaves the business offline for days or weeks. Restoring last night's backup onto new hardware discards a replica that is only seconds behind in favor of data that is many hours old, increasing both downtime and data loss. Promoting the secondary while leaving DNS pointing to the destroyed primary leaves the applications unable to connect, so the service remains down even though a healthy primary exists. Exam caveat: asynchronous replication means a small amount of data loss on failover, which should fall within the agreed recovery point objective. Operational check: after failover, confirm the DNS change has propagated to application servers, any cached connections were refreshed, and a test transaction commits on the new primary.