Examine scaling options in Azure Container Apps
Azure Container Apps manages automatic horizontal scaling through a set of declarative scaling rules. As a container app revision scales out, new instances of the revision are created on-demand. These instances are known as replicas.
Adding or editing scaling rules creates a new revision of your container app. A revision is an immutable snapshot of your container app.
Scale definition
Scaling is defined by the combination of limits, rules, and behavior.
- Limits are the minimum and maximum possible number of replicas per revision as your container app scales.Scale limitDefault valueMin valueMax valueMinimum number of replicas per revision001000Maximum number of replicas per revision1011000To request an increase in maximum replica amounts for your container app, submit a support ticket.
- Rules are the criteria used by Container Apps to decide when to add or remove replicas.Scale rules are implemented as HTTP, TCP (Transmission Control Protocol), or custom.
- Behavior is how the rules and limits are combined together to determine scale decisions over time.Scale behavior explains how scale decisions are calculated.
As you define your scaling rules, it’s important to consider the following items:
- You aren’t billed usage charges if your container app scales to zero.
- Replicas that aren’t processing, but remain in memory might be billed at a lower “idle” rate.
- If you want to ensure that an instance of your revision is always running, set the minimum number of replicas to 1 or higher.