Multi-Tenant LMS Infrastructure Deployment with Kubernetes

Design a scalable Kubernetes architecture for a multi-tenant learning management system that can securely isolate student and institutional data across different namespaces. Create a comprehensive deployment strategy that includes automated pod scaling, network policies to prevent inter-tenant data leakage, and a robust ingress configuration using Istio service mesh. Include specific considerations for handling peak enrollment periods, ensuring zero-downtime upgrades, and implementing granular RBAC controls for different user roles like administrators, teachers, and students.