ScalableTarget

Source: src/AWS/ApplicationAutoScaling/ScalableTarget.ts

An Application Auto Scaling scalable target — registers a resource’s capacity dimension (an ECS service’s desired count, a DynamoDB table’s read capacity, Lambda provisioned concurrency, …) so that scaling policies and scheduled actions can act on it.

A scalable target is uniquely identified by the (serviceNamespace, resourceId, scalableDimension) triple; changing any part of the triple replaces the target. Deregistering a scalable target deletes the scaling policies and scheduled actions associated with it.

Creating Scalable Targets

Scale an ECS Service

const target = yield* ScalableTarget("ApiScaling", {
  serviceNamespace: "ecs",
  resourceId: Output.interpolate`service/${cluster.clusterName}/${service.serviceName}`,
  scalableDimension: "ecs:service:DesiredCount",
  minCapacity: 1,
  maxCapacity: 3,
});

Scale DynamoDB Read Capacity

const target = yield* ScalableTarget("TableReadScaling", {
  serviceNamespace: "dynamodb",
  resourceId: Output.interpolate`table/${table.tableName}`,
  scalableDimension: "dynamodb:table:ReadCapacityUnits",
  minCapacity: 1,
  maxCapacity: 10,
});

Suspending Scaling

yield* ScalableTarget("ApiScaling", {
  serviceNamespace: "ecs",
  resourceId: Output.interpolate`service/${cluster.clusterName}/${service.serviceName}`,
  scalableDimension: "ecs:service:DesiredCount",
  minCapacity: 1,
  maxCapacity: 3,
  suspendedState: { DynamicScalingInSuspended: true },
});