An application in one GKE cluster must call a REST service deployed in two GKE clusters in different regions. How should you connect and configure health checks? (Choose two.)

Cloud Service Mesh (powered by Istio) with sidecar proxies is the recommended approach for connecting services across multiple GKE clusters, especially when those clusters are in different regions. Sidecar proxies handle traffic management, load balancing, and observability, making cross-cluster communication robust and manageable. While proxyless gRPC is an option for specific gRPC services, sidecar proxies offer broader applicability for REST services and general traffic management. For health checks, GKE's health check probes originate from specific, documented IP ranges. To ensure your REST service is properly monitored and remains available, you must configure your firewall to allow incoming connections from these GKE health check probe IP ranges. Allowing GKE Service IP ranges or GKE control plane IP ranges would be incorrect as these are not the sources for health check probes.