Examkin

Question

Difficulty: MediumDisaster Recovery and Business Continuity Execution

An enterprise financial transaction platform running on Google Cloud maintains a warm standby disaster recovery setup in region `us-east4` to handle regional failures of its primary environment in `us-central1`. Following a catastrophic loss of `us-central1`, the cloud architecture team must initiate the regional failover runbook. Arrange the following execution steps in the correct chronological sequence from first to last.

  1. 1Promote the cross-region database read replica in `us-east4` to a standalone primary instance.
  2. 2Scale up the secondary region Compute Engine Managed Instance Groups (MIGs) from standby capacity to full operational capacity.
  3. 3Reconfigure the Global HTTP(S) Load Balancer backend services to point to the scaled instance groups in `us-east4`.
  4. 4Update Cloud DNS health-checked routing policies to complete external client traffic redirection to the failover endpoint.

Answer

The correct chronological sequence for regional failover execution is: 1) Promote the cross-region database read replica to primary status, 2) Scale up the secondary Managed Instance Groups to full production capacity, 3) Reconfigure the Global HTTP(S) Load Balancer backend services to target the secondary region, and 4) Update Cloud DNS routing policies to finalize domain redirection.
Executing a disaster recovery failover requires establishing data write availability first (promoting the database replica), expanding compute capacity second (scaling MIGs), switching internal traffic routing third (updating Load Balancer backends), and finalizing external ingress routing last (updating DNS policies). This order guarantees zero write-block failures and prevents capacity overload.

Step-by-Step Solution

1
Establish persistence write capability by promoting the secondary database replica.
Database write availability is restored in the target disaster recovery region (`us-east4`).
Promoting the database replica first prevents application connection failures and data corruption when application instances spin up.
2
Provision required compute workload capacity in the disaster recovery region.
Managed Instance Groups in `us-east4` expand to meet production traffic demands.
Application nodes must be fully scaled and running healthy instances before accepting production traffic workloads.
3
Shift global load balancing target backends to the newly scaled instance groups.
Load balancer health checks pass and traffic is pointed to secondary regional backends.
Updating backend service definitions directs regional ingress traffic toward active compute resources.
4
Update Cloud DNS routing policies to broadcast the endpoint shift globally.
External client traffic transitions entirely to the active disaster recovery environment.
DNS update is the external entry point change that completes the end-to-end failover sequence.

Key Concept

Disaster Recovery Regional Failover Execution Sequence
Estimated Time:2m 0s
Rate this question

Topics

Disaster Recovery and Business Continuity Execution

More questions from this topic