feat(aws-ecs): ECS service scaling on ALB RequestCount (#1574)

aws · Jan 23, 2019 · 8a73877 · 8a73877
1 parent fd1f3a6
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diff --git a/packages/@aws-cdk/aws-ecs/README.md b/packages/@aws-cdk/aws-ecs/README.md
@@ -205,7 +205,7 @@ const service = new ecs.FargateService(this, 'Service', { /* ... */ });
 
 const lb = new elbv2.ApplicationLoadBalancer(this, 'LB', { vpc, internetFacing: true });
 const listener = lb.addListener('Listener', { port: 80 });
-listener.addTargets('ECS', {
+const target = listener.addTargets('ECS', {
  port: 80,
  targets: [service]
 });
@@ -226,6 +226,11 @@ const scaling = service.autoScaleTaskCount({ maxCapacity: 10 });
 scaling.scaleOnCpuUtilization('CpuScaling', {
  targetUtilizationPercent: 50
 });
+
+scaling.scaleOnRequestCount('RequestScaling', {
+ requestsPerTarget: 10000,
+ targetGroup: target
+})
 ```
 
 Task AutoScaling is powered by *Application AutoScaling*. Refer to that for

diff --git a/packages/@aws-cdk/aws-ecs/lib/base/scalable-task-count.ts b/packages/@aws-cdk/aws-ecs/lib/base/scalable-task-count.ts
@@ -1,5 +1,6 @@
 import appscaling = require('@aws-cdk/aws-applicationautoscaling');
 import cloudwatch = require('@aws-cdk/aws-cloudwatch');
+import elbv2 = require('@aws-cdk/aws-elasticloadbalancingv2');
 
 /**
  * Scalable attribute representing task count
@@ -29,21 +30,39 @@ export class ScalableTaskCount extends appscaling.BaseScalableAttribute {
  disableScaleIn: props.disableScaleIn,
  targetValue: props.targetUtilizationPercent,
  scaleInCooldownSec: props.scaleInCooldownSec,
- scaleOutCooldownSec: props.scaleOutCooldownSec,
+ scaleOutCooldownSec: props.scaleOutCooldownSec
  });
  }
 
  /**
- * Scale out or in to achieve a target memory utilization utilization
+ * Scale out or in to achieve a target memory utilization
  */
- public scaleOnMemoryUtilization(id: string, props: CpuUtilizationScalingProps) {
+ public scaleOnMemoryUtilization(id: string, props: MemoryUtilizationScalingProps) {
  return super.doScaleToTrackMetric(id, {
  predefinedMetric: appscaling.PredefinedMetric.ECSServiceAverageMemoryUtilization,
  targetValue: props.targetUtilizationPercent,
  policyName: props.policyName,
  disableScaleIn: props.disableScaleIn,
  scaleInCooldownSec: props.scaleInCooldownSec,
- scaleOutCooldownSec: props.scaleOutCooldownSec,
+ scaleOutCooldownSec: props.scaleOutCooldownSec
+ });
+ }
+
+ /**
+ * Scale out or in to achieve a target ALB request count per target
+ */
+ public scaleOnRequestCount(id: string, props: RequestCountScalingProps) {
+ const resourceLabel = props.targetGroup.firstLoadBalancerFullName +
+ '/' + props.targetGroup.targetGroupFullName;
+
+ return super.doScaleToTrackMetric(id, {
+ predefinedMetric: appscaling.PredefinedMetric.ALBRequestCountPerTarget,
+ resourceLabel,
+ targetValue: props.requestsPerTarget,
+ policyName: props.policyName,
+ disableScaleIn: props.disableScaleIn,
+ scaleInCooldownSec: props.scaleInCooldownSec,
+ scaleOutCooldownSec: props.scaleOutCooldownSec
  });
  }
 
@@ -82,6 +101,21 @@ export interface MemoryUtilizationScalingProps extends appscaling.BaseTargetTrac
  targetUtilizationPercent: number;
 }
 
+/**
+ * Properties for enabling scaling based on ALB request counts
+ */
+export interface RequestCountScalingProps extends appscaling.BaseTargetTrackingProps {
+ /**
+ * ALB requests per target
+ */
+ requestsPerTarget: number;
+
+ /**
+ * ALB Target Group
+ */
+ targetGroup: elbv2.ApplicationTargetGroup;
+}
+
 /**
  * Properties to target track a custom metric
  */

diff --git a/packages/@aws-cdk/aws-ecs/test/fargate/test.fargate-service.ts b/packages/@aws-cdk/aws-ecs/test/fargate/test.fargate-service.ts
@@ -1,5 +1,6 @@
 import { expect, haveResource, haveResourceLike } from '@aws-cdk/assert';
 import ec2 = require('@aws-cdk/aws-ec2');
+import elbv2 = require("@aws-cdk/aws-elasticloadbalancingv2");
 import cdk = require('@aws-cdk/cdk');
 import { Test } from 'nodeunit';
 import ecs = require('../../lib');
@@ -156,4 +157,59 @@ export = {
  test.done();
  },
  },
+
+ "When adding an app load balancer": {
+ 'allows auto scaling by ALB request per target'(test: Test) {
+ // GIVEN
+ const stack = new cdk.Stack();
+ const vpc = new ec2.VpcNetwork(stack, 'MyVpc', {});
+ const cluster = new ecs.Cluster(stack, 'EcsCluster', { vpc });
+ const taskDefinition = new ecs.FargateTaskDefinition(stack, 'FargateTaskDef');
+ const container = taskDefinition.addContainer('MainContainer', {
+ image: ContainerImage.fromDockerHub('hello'),
+ });
+ container.addPortMappings({ containerPort: 8000 });
+ const service = new ecs.FargateService(stack, 'Service', { cluster, taskDefinition });
+
+ const lb = new elbv2.ApplicationLoadBalancer(stack, "lb", { vpc });
+ const listener = lb.addListener("listener", { port: 80 });
+ const targetGroup = listener.addTargets("target", {
+ port: 80,
+ targets: [service]
+ });
+
+ // WHEN
+ const capacity = service.autoScaleTaskCount({ maxCapacity: 10, minCapacity: 1 });
+ capacity.scaleOnRequestCount("ScaleOnRequests", {
+ requestsPerTarget: 1000,
+ targetGroup
+ });
+
+ // THEN
+ expect(stack).to(haveResource('AWS::ApplicationAutoScaling::ScalableTarget', {
+ MaxCapacity: 10,
+ MinCapacity: 1
+ }));
+
+ expect(stack).to(haveResource('AWS::ApplicationAutoScaling::ScalingPolicy', {
+ TargetTrackingScalingPolicyConfiguration: {
+ PredefinedMetricSpecification: {
+ PredefinedMetricType: "ALBRequestCountPerTarget",
+ ResourceLabel: {
+ "Fn::Join": ["", [
+ { "Fn::Select": [1, { "Fn::Split": ["/", { Ref: "lblistener657ADDEC" }] }] }, "/",
+ { "Fn::Select": [2, { "Fn::Split": ["/", { Ref: "lblistener657ADDEC" }] }] }, "/",
+ { "Fn::Select": [3, { "Fn::Split": ["/", { Ref: "lblistener657ADDEC" }] }] }, "/",
+ { "Fn::GetAtt": ["lblistenertargetGroupC7489D1E", "TargetGroupFullName"] }
+ ]]
+ }
+ },
+ TargetValue: 1000
+ }
+ }));
+
+ test.done();
+ }
+
+ }
 };