In cloud disaster recovery, which architecture keeps only minimal core services always on and replicates other components as needed?

• A. Hot standby
• B. Warm standby
• C. Pilot light
• D. Cold standby

Answer: (C)

This approach in cloud disaster recovery centers on cost efficiency by keeping only the smallest set of essential services running at all times while the rest of the environment is replicated and can be brought online as needed. This is the pilot light design. In normal operations, only the critical components—such as core data stores and essential identity or configuration services—remain active, which keeps ongoing costs low. When a disaster occurs, you scale up by provisioning the remaining components and restoring any required data from the replicated copies to bring the full environment online. This setup offers a balance between speed and cost: faster recovery than starting from scratch, but not as fast as keeping a full production environment live in the DR site. The other architectures either maintain a full environment continuously (hot standby), keep a larger pre-warmed subset (warm standby), or keep nothing running until failover (cold standby), each with different costs and recovery times.