You want to implement an auto-scaling, fault-tolerant microservices architecture. You also need to collect logs and metrics. What combination of GCP services would you choose?

GKE (Google Kubernetes Engine) provides a managed environment for deploying and managing containerized applications, making it ideal for microservices. Istio is a service mesh that adds advanced traffic management, security, and observability features, crucial for fault-tolerant microservices. Cloud Monitoring collects logs and metrics from GKE and Istio, offering comprehensive visibility. App Engine is a platform-as-a-service, less flexible for custom microservices than GKE. Cloud Endpoints is for API management, not core microservices orchestration. Cloud Trace is for distributed tracing, not general logging and metrics. Cloud Run is serverless, but Istio is not directly integrated for service mesh capabilities. Envoy is a proxy, but Istio provides a complete service mesh solution. Cloud Logging is for logs, but Cloud Monitoring is for both logs and metrics. Cloud Armor is a DDoS protection and WAF service, not directly related to microservices orchestration or monitoring. Cloud Debugger is for debugging, not monitoring.