Google Cloud Professional Data Engineer Exam

Setting up automatic failover is the most effective way to achieve the highest availability for a production Cloud SQL database. Automatic failover ensures that if the primary instance of the database becomes unavailable due to hardware failure, maintenance, or other issues, a standby instance can take over automatically with minimal disruption. This process significantly reduces downtime, allowing applications to continue running smoothly without requiring manual intervention.

For mission-critical applications where uptime is paramount, automatic failover is crucial because it provides a seamless fallback mechanism, ensuring that users experience minimal service interruption. The standby instance, generally located in the same or a different region, can quickly take over, maintaining data availability and integrity.

While other options like implementing a read replica, using horizontal scaling, and regularly backing up the database are important aspects of cloud database management, they do not directly contribute to automatic recovery during a failure. Read replicas help with load balancing and reporting but do not replace the primary instance during downtimes. Horizontal scaling pertains to increasing capacity by adding more instances, but it doesn't address failover. Regular backups ensure data can be restored in the event of loss, but they do not prevent downtime; backups are reactive rather than proactive solutions for availability. Thus, setting up automatic failover distinctly provides the highest level of