Which components handle AKS state, pub/sub, and traffic splitting?

Why the Answer Is Correct

Dapr's state management building block gives microservices a standardized key-value API (save, get, delete) over backends such as Azure Cache for Redis or Azure Cosmos DB, so no service writes engine-specific state code and administrative effort stays low. Dapr's pub/sub building block likewise abstracts the broker (Azure Service Bus, Redis Streams, Kafka) behind a consistent publish/subscribe API with CloudEvents and at-least-once delivery. Traffic routing and splitting — canary, blue/green, weighted versions — is a layer-7 service-mesh concern handled by Istio's VirtualService and DestinationRule weight fields. Because AKS offers a managed Istio-based service mesh add-on, the routing requirement is met without operating your own control plane, satisfying the 'minimize administrative effort' constraint.

Why Other Candidate Answers Are Wrong

Assigning Istio to state management or pub/sub messaging fails because a service mesh routes and secures traffic; it has no application state store API and no publish/subscribe abstraction, so each microservice would have to bind directly to a broker or database SDK. Assigning Dapr to traffic routing and splitting fails because Dapr's building blocks target application concerns (state, pub/sub, service invocation, secrets) and do not provide weighted layer-7 traffic distribution across service versions. GitOps tools such as Flux only reconcile deployment manifests and cannot hold state or split traffic, and event-driven autoscalers such as KEDA scale workloads but never route or persist anything. Mixing one tool across all three functions therefore breaks at least one requirement.

Community Comment Notes

Ras1364 recorded exactly the same mapping — Dapr for state management, Dapr for pub/sub messaging, and Istio for traffic routing and splitting — which matches the vendor's body of knowledge for AKS microservices. Splash04 reasoned that state management and pub/sub should both be Dapr because "publish/subscribe is one of Dapr's core application-level building blocks", while Istio is "a service mesh designed for traffic management". gpais added that Dapr offers a "dedicated State Management building block" that works across backends like Redis or Cosmos DB, and pointed out that neither a GitOps deployment tool nor a service mesh handles application state. The consensus across these comments is consistent with the answer given here, and no comment proposes a viable alternative mapping.