Your enterprise runs a hybrid multi-cluster architecture spanning an on-premises GKE cluster and multiple Google Cloud GKE clusters managed by Cloud Service Mesh. You need to implement an automated traffic routing and deployment strategy that meets the following operational requirements: Cost Optimization: Client requests must prioritize on-premises compute resources (registered via hybrid connectivity Network Endpoint Groups) up to their maximum capacity before routing excess traffic to autoscaling Google Cloud GKE backends. Automated Failure Protection: If an on-premises backend group experiences severe degradation with fewer than 25% of endpoints passing health checks, traffic must automatically shift away from the degraded group without manual intervention to protect surviving endpoints from cascade failure. Which Cloud Service Mesh configuration should you implement?

Designate the on-premises hybrid connectivity NEGs as preferred backends and enable automatic capacity draining on the backend service.: ### What Preferred Backends and Automatic Capacity Draining Are **Preferred backends** and **automatic capacity draining** are advanced traffic routing and resilience capabilities provided by **Cloud Service Mesh** (Anthos Service Mesh) for backend services. Preferred backends designate specific groups of endpoints—such as on-premises infrastructure represented by **hybrid connectivity Network Endpoint Groups (NEGs)**—to receive client requests first until their provisioned capacity is saturated. **Automatic capacity draining** continuously monitors the health status of individual endpoints within a backend group and automatically scales down the backend's capacity scaler to zero when health check passing rates fall below defined failure thresholds. ### How It Meets the Requirements - **Cost Optimization**: Configuring on-premises hybrid connectivity NEGs as preferred backends ensures that local on-premises compute capacity is fully utilized before any requests are spilled over to autoscaled Google Cloud GKE backends, minimizing cloud compute costs during baseline traffic. - **Automated Failure Protection**: When the health check passing rate of a backend falls below **25%**, automatic capacity draining instantly excludes that backend from global load balancing decisions, preventing cascading failures across the remaining healthy instances in that group. ### Key Advantages and Capabilities - **Automated Failover and Overflow**: Enables smooth overflow to Google Cloud during traffic spikes and failover during local infrastructure incidents. - **Hysteresis Recovery**: Reintegrates drained backends automatically once at least **35%** of endpoints remain healthy continuously for **60 seconds**. - **Blast Radius Protection**: Limits automatic draining so that no more than **50%** of total backend service endpoints can be drained simultaneously, preventing total traffic blackholing. - **Zero-Touch Traffic Engineering**: Operates dynamically at the control plane and data plane levels without requiring manual configuration updates or CI/CD script interventions. ### Why This Is Optimal This solution natively satisfies both cost-containment and high-availability criteria using built-in Cloud Service Mesh traffic policies. It eliminates the operational lag and fragility of external automation scripts while managing hybrid multi-cluster routing seamlessly.

Cloud Service Mesh Hybrid Preferred Backends Capacity Draining | Professional Cloud DevOps Engineer

Cloud Service Mesh Hybrid Preferred Backends Capacity Draining

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Your enterprise runs a hybrid multi-cluster architecture spanning an on-premises GKE cluster and multiple Google Cloud GKE clusters managed by Cloud Service Mesh. You need to implement an automated traffic routing and deployment strategy that meets the following operational requirements:

Cost Optimization: Client requests must prioritize on-premises compute resources (registered via hybrid connectivity Network Endpoint Groups) up to their maximum capacity before routing excess traffic to autoscaling Google Cloud GKE backends.
Automated Failure Protection: If an on-premises backend group experiences severe degradation with fewer than 25% of endpoints passing health checks, traffic must automatically shift away from the degraded group without manual intervention to protect surviving endpoints from cascade failure.

Which Cloud Service Mesh configuration should you implement?

Configure the global load balancing algorithm to spray to world and apply an outlier detection policy across all cluster endpoints.

Designate the Google Cloud GKE NEGs as preferred backends and configure weighted canary routing with a 50/50 traffic split in the VirtualService definition.

Designate the on-premises hybrid connectivity NEGs as preferred backends and enable automatic capacity draining on the backend service.

Set the load balancing algorithm to waterfall by zone and deploy an external monitoring cron job to modify the capacityScaler attribute via the Cloud SDK when alerts fire.

Professional Cloud DevOps Engineer

Cloud Service Mesh Hybrid Preferred Backends Capacity Draining

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