Functions Premium plan

Security for Functions Premium plan starts with VNet integration, private dependency access, managed identity, app settings, deployment permissions, plan sharing, diagnostic access, publishing credentials, and network paths opened for functions. Review who can create, update, list, rotate, swap, publish, replicate, read diagnostics, or use the resource. Prefer Microsoft Entra ID, managed identity, least privilege, private networking, secure transfer, and audited automation where the service supports them. Keep secrets out of code and avoid public exposure unless a documented exception exists. Capture role assignments, Activity Log entries, diagnostic settings, policy decisions, and owner approvals so access and data handling are intentional.

Cost for Functions Premium plan is driven by prewarmed instances, worker size, always-ready capacity, max burst, idle apps on shared plans, Application Insights ingestion, private networking, duplicate test plans, and overestimated latency needs. The expensive mistake is not only Azure consumption; it can also be failed releases, duplicate environments, over-retained images, unnecessary diagnostic volume, idle premium capacity, emergency support, or cleanup after weak design evidence. Review whether the workload truly needs the selected tier, replicas, runtime plan, retention, redundancy, access tier, monitoring, or automation pattern. Use tags, budgets, alerts, and cleanup reviews so teams can explain why the design exists.

Reliability for Functions Premium plan depends on minimum ready capacity, maximum burst, regional capacity, trigger scaling, dependency availability, app distribution across plans, runtime health, and rollback from plan or SKU changes. A resource can exist and still fail the business workflow if versioning, slot state, runtime support, trigger health, image replication, storage redundancy, network rules, or downstream services are wrong. Test failure modes, deployment behavior, rollback steps, monitoring signals, and maintenance windows before relying on the design. During incidents, compare logs, metrics, configuration, deployment history, and application traces from the same time window before changing production. Review owner, scope, evidence, dependencies, and rollback before production change.

Performance for Functions Premium plan depends on always-ready capacity, cold start reduction, CPU and memory size, event backlog, trigger concurrency, VNet latency, dependency initialization, package size, and scale-out speed. Measure platform metrics and workload completion times because a healthy control-plane response does not prove users received the right result. Test with realistic regions, data sizes, package sizes, image replication, trigger load, identity paths, network routes, cache state, and downstream limits. When performance regresses, compare configuration changes, resource limits, client logs, diagnostic data, and workload timing before adding capacity or blaming one service. Review owner, scope, evidence, dependencies, and rollback before production change.

Operations for Functions Premium plan require capacity reviews, min-instance approvals, scale dashboards, cost alerts, app-to-plan inventories, private-network evidence, deployment windows, and runbooks for throttling or cold-start incidents. Before a change, capture read-only CLI output, portal evidence when useful, owner tags, dependency lists, expected behavior, and rollback steps. During incidents, avoid changing several settings at once; compare metrics, logs, deployment operations, identity evidence, network state, and downstream health first. Keep runbooks clear enough for support teams to verify current behavior quickly. Good operations make the term observable, reviewable, and recoverable during releases, audits, and incidents. Review owner, scope, evidence, dependencies, and rollback before production change.