Which technology provides event-driven scale rules in Container Apps?
Why D is the answer
KEDA
KEDA scales on event sources such as queue length, including down to zero.
In detail
- KEDA provides event-driven scale rules.
- KEDA has scalers for many event sources.
Use case
An illustrative scenario, not a real incident.
A worker scales with a storage queue through a KEDA rule in Container Apps, with no custom scaling code.
See it in different ways
flowchart LR A["Queue length grows"] --> B["KEDA scale rule"] B --> C["More replicas"] C --> D["Queue drains"] D --> E["Scale to zero"]
stateDiagram-v2 [*] --> Zero Zero --> Running: messages arrive Running --> MoreReplicas: queue grows MoreReplicas --> Running: queue shrinks Running --> Zero: queue is empty
flowchart LR S0["Event source"] --> S1["KEDA rule"] --> S2["Replicas change"]
Key point: KEDA provides event-driven scale rules.
Why the other options are wrong
- A. A Dockerfile instruction that sets the number of replicas
- A Dockerfile cannot set replicas.
- B. Azure Key Vault secret rotation
- Key Vault is about secrets.
- C. A DNS record that points at a second replica
- DNS does not scale anything.