Service catalog

IaaS compute. Resiliency is entirely a function of how many instances you run and where you place them — a single VM has no failover story at all.

The AKS SLA only ever covers the Kubernetes API server, never your workloads. There is no native multi-region failover for a cluster — cross-region resilience is a fully custom architecture.

Zone redundancy requires Premium v2/v3+ and a minimum instance count. There is no native regional failover feature — multi-region App Service is Front Door/Traffic Manager plus a second, independently deployed app.

Redundancy is set per storage account via the SKU (LRS/ZRS/GRS/GZRS). Geo-redundant tiers replicate to the paired region, but write access after a regional outage requires a failover you trigger yourself.

Zone-redundant HA (Premium/Business Critical/Hyperscale) is synchronous and near-instant. Cross-region continuity via auto-failover groups is asynchronous and, per Microsoft's own guidance, should be triggered by you — not left to the 'automatic' policy.

The best-positioned data service in this catalog for tight RPO/RTO — but only if you explicitly enable Per-Partition Automatic Failover (PPAF). The default 'service-managed failover' setting most teams reach for can take an hour or more to trigger.

Every SKU of this service is on Microsoft's announced retirement path toward Azure Managed Redis — any resiliency plan built today should target the replacement service. Geo-replication here has no guaranteed recovery point.

In-region resiliency (including zone spread, where supported) is fully automatic and not user-configurable. Cross-region DR does not exist as a platform feature — you build and maintain a second vault yourself.

The legacy Geo-DR feature — still what most existing docs and architectures reference — replicates namespace metadata only, not messages. The newer Geo-Replication feature (Premium) replicates message data too, but promotion is always customer-triggered.

Zone redundancy is automatic and transparent on Standard/Premium/Dedicated. Cross-region DR (Dedicated/Premium only) replicates namespace metadata only — unlike Service Bus, there is no message-data-replicating alternative.

Load Balancer and Application Gateway are regional services — zone resiliency only. Azure Front Door is the actual cross-region failover mechanism for HTTP(S) traffic, via automated health-probe-based routing.

Zone-redundant gateway VMs are automatic on eligible SKUs — Azure explicitly states you don't need to initiate or validate zone failover. A gateway is always a single-region resource, though: regional DR means deploying independent gateways yourself.

The general-purpose recovery mechanism behind most other services in this catalog. Backup gives point-in-time restore (RPO = policy schedule); Site Recovery gives a continuously-replicating standby with orchestrated, still-manual failover. Neither is fast enough for Tier 0/1 on its own.