AWS SDK を使用した Amazon DynamoDB テーブルでの Auto Scaling の設定

AWS Management Console と AWS Command Line Interface (AWS CLI) を使用するほかに、Amazon DynamoDB Auto Scaling とやり取りするアプリケーションを作成することもできます。このセクションには、この機能をテストするために使用できる 2 つの Java プログラムが含まれています。

• EnableDynamoDBAutoscaling.java

• DisableDynamoDBAutoscaling.java

テーブルの Application Auto Scaling の有効化

次のプログラムは、DynamoDB テーブル (TestTable) の Auto Scaling ポリシーをセットアップする例を示しています。プログラムの流れは次のようになります。

• TestTable のスケーラブルなターゲットとして書き込みキャパシティユニットを登録します。このメトリクスの範囲は 5 ～ 10 書き込みキャパシティーユニットです。

• スケーラブルなターゲットを作成したら、次にターゲットの追跡設定を作成します。このポリシーでは、プロビジョニングされた書き込みキャパシティに対する消費された書き込みキャパシティの割合を 50% に維持することを目指します。

• 次に、ターゲットの追跡設定に基づいてスケーリングポリシーを作成します。

注記

テーブルまたはグローバルテーブルレプリカを手動で削除しても、関連するスケーラブルターゲット、スケーリングポリシー、または CloudWatch アラームは自動的には削除されません。

プログラムでは、有効な Application Auto Scaling サービスリンクロールの Amazon リソースネーム (ARN) を指定する必要があります。(例: arn:aws:iam::122517410325:role/AWSServiceRoleForApplicationAutoScaling_DynamoDBTable。) 次のプログラムの SERVICE_ROLE_ARN_GOES_HERE を実際の ARN に置き換えます。

/**
 * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * This file is licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License. A copy of
 * the License is located at
 *
 * http://aws.amazon.com/apache2.0/
 *
 * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
*/
package com.amazonaws.codesamples.autoscaling;

import com.amazonaws.services.applicationautoscaling.AWSApplicationAutoScalingClient;
import com.amazonaws.services.applicationautoscaling.AWSApplicationAutoScalingClientBuilder;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsResult;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesResult;
import com.amazonaws.services.applicationautoscaling.model.MetricType;
import com.amazonaws.services.applicationautoscaling.model.PolicyType;
import com.amazonaws.services.applicationautoscaling.model.PredefinedMetricSpecification;
import com.amazonaws.services.applicationautoscaling.model.PutScalingPolicyRequest;
import com.amazonaws.services.applicationautoscaling.model.RegisterScalableTargetRequest;
import com.amazonaws.services.applicationautoscaling.model.ScalableDimension;
import com.amazonaws.services.applicationautoscaling.model.ServiceNamespace;
import com.amazonaws.services.applicationautoscaling.model.TargetTrackingScalingPolicyConfiguration;

public class EnableDynamoDBAutoscaling {

    static AWSApplicationAutoScalingClient aaClient = (AWSApplicationAutoScalingClient) AWSApplicationAutoScalingClientBuilder.standard().build();

    public static void main(String args[]) {

	ServiceNamespace ns = ServiceNamespace.Dynamodb;
	ScalableDimension tableWCUs = ScalableDimension.DynamodbTableWriteCapacityUnits;
	String resourceID = "table/TestTable";

	// Define the scalable target
	RegisterScalableTargetRequest rstRequest = new RegisterScalableTargetRequest()
		.withServiceNamespace(ns)
		.withResourceId(resourceID)
		.withScalableDimension(tableWCUs)
		.withMinCapacity(5)
		.withMaxCapacity(10)
		.withRoleARN("SERVICE_ROLE_ARN_GOES_HERE");
	
	try {
	    aaClient.registerScalableTarget(rstRequest);
	} catch (Exception e) {
	    System.err.println("Unable to register scalable target: ");
	    System.err.println(e.getMessage());
	}

	// Verify that the target was created
	DescribeScalableTargetsRequest dscRequest = new DescribeScalableTargetsRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceIds(resourceID);
	try {
	    DescribeScalableTargetsResult dsaResult = aaClient.describeScalableTargets(dscRequest);
	    System.out.println("DescribeScalableTargets result: ");
	    System.out.println(dsaResult);
	    System.out.println();
	} catch (Exception e) {
	    System.err.println("Unable to describe scalable target: ");
	    System.err.println(e.getMessage());
	}
	
	System.out.println();

	// Configure a scaling policy
	TargetTrackingScalingPolicyConfiguration targetTrackingScalingPolicyConfiguration = 
		new TargetTrackingScalingPolicyConfiguration()
		.withPredefinedMetricSpecification(
			new PredefinedMetricSpecification()
			.withPredefinedMetricType(MetricType. DynamoDBWriteCapacityUtilization))
		.withTargetValue(50.0)
		.withScaleInCooldown(60)
		.withScaleOutCooldown(60);

	// Create the scaling policy, based on your configuration
	PutScalingPolicyRequest pspRequest = new PutScalingPolicyRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceId(resourceID)
		.withPolicyName("MyScalingPolicy")
		.withPolicyType(PolicyType.TargetTrackingScaling)
		.withTargetTrackingScalingPolicyConfiguration(targetTrackingScalingPolicyConfiguration);
	
	try {
	    aaClient.putScalingPolicy(pspRequest);
	} catch (Exception e) {
	    System.err.println("Unable to put scaling policy: ");
	    System.err.println(e.getMessage());
	}

	// Verify that the scaling policy was created
	DescribeScalingPoliciesRequest dspRequest = new DescribeScalingPoliciesRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceId(resourceID);
	
	try {
	    DescribeScalingPoliciesResult dspResult = aaClient.describeScalingPolicies(dspRequest);
	    System.out.println("DescribeScalingPolicies result: ");
	    System.out.println(dspResult);
	} catch (Exception e) {
	    e.printStackTrace();
	    System.err.println("Unable to describe scaling policy: ");
	    System.err.println(e.getMessage());
	}

    }

}

テーブルの Application Auto Scaling の無効化

次のプログラムは、前述のプロセスを元に戻します。Auto Scaling ポリシーを削除し、スケーラブルなターゲットを登録解除します。

/**
 * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * This file is licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License. A copy of
 * the License is located at
 *
 * http://aws.amazon.com/apache2.0/
 *
 * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
*/
package com.amazonaws.codesamples.autoscaling;

import com.amazonaws.services.applicationautoscaling.AWSApplicationAutoScalingClient;
import com.amazonaws.services.applicationautoscaling.model.DeleteScalingPolicyRequest;
import com.amazonaws.services.applicationautoscaling.model.DeregisterScalableTargetRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalableTargetsResult;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import com.amazonaws.services.applicationautoscaling.model.DescribeScalingPoliciesResult;
import com.amazonaws.services.applicationautoscaling.model.ScalableDimension;
import com.amazonaws.services.applicationautoscaling.model.ServiceNamespace;

public class DisableDynamoDBAutoscaling {

    static AWSApplicationAutoScalingClient aaClient = new AWSApplicationAutoScalingClient();

    public static void main(String args[]) {

	ServiceNamespace ns = ServiceNamespace.Dynamodb;
	ScalableDimension tableWCUs = ScalableDimension.DynamodbTableWriteCapacityUnits;
	String resourceID = "table/TestTable";

	// Delete the scaling policy
	DeleteScalingPolicyRequest delSPRequest = new DeleteScalingPolicyRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceId(resourceID)
		.withPolicyName("MyScalingPolicy");
	
	try {
	    aaClient.deleteScalingPolicy(delSPRequest);
	} catch (Exception e) {
	    System.err.println("Unable to delete scaling policy: ");
	    System.err.println(e.getMessage());
	}

	// Verify that the scaling policy was deleted
	DescribeScalingPoliciesRequest descSPRequest = new DescribeScalingPoliciesRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceId(resourceID);
	
	try {
	    DescribeScalingPoliciesResult dspResult = aaClient.describeScalingPolicies(descSPRequest);
	    System.out.println("DescribeScalingPolicies result: ");
	    System.out.println(dspResult);
	} catch (Exception e) {
	    e.printStackTrace();
	    System.err.println("Unable to describe scaling policy: ");
	    System.err.println(e.getMessage());
	}
	
	System.out.println();

	// Remove the scalable target
	DeregisterScalableTargetRequest delSTRequest = new DeregisterScalableTargetRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceId(resourceID);

	try {
	    aaClient.deregisterScalableTarget(delSTRequest);
	} catch (Exception e) {
	    System.err.println("Unable to deregister scalable target: ");
	    System.err.println(e.getMessage());
	}

	// Verify that the scalable target was removed
	DescribeScalableTargetsRequest dscRequest = new DescribeScalableTargetsRequest()
		.withServiceNamespace(ns)
		.withScalableDimension(tableWCUs)
		.withResourceIds(resourceID);

	try {
	    DescribeScalableTargetsResult dsaResult = aaClient.describeScalableTargets(dscRequest);
	    System.out.println("DescribeScalableTargets result: ");
	    System.out.println(dsaResult);
	    System.out.println();
	} catch (Exception e) {
	    System.err.println("Unable to describe scalable target: ");
	    System.err.println(e.getMessage());
	}

    }

}