使用适用于 Java 的 SDK 2.x 的 Auto Scaling 示例

以下代码示例向您展示了如何使用与 Application Auto Scaling Amazon SDK for Java 2.x 配合使用来执行操作和实现常见场景。

操作是大型程序的代码摘录，必须在上下文中运行。您可以通过操作了解如何调用单个服务函数，还可以通过函数相关场景和跨服务示例的上下文查看操作。

场景是展示如何通过在同一服务中调用多个函数来完成特定任务的代码示例。

每个示例都包含一个指向的链接 GitHub，您可以在其中找到有关如何在上下文中设置和运行代码的说明。

主题

操作

操作

以下代码示例演示了如何使用 DeleteScalingPolicy。

适用于 Java 2.x 的 SDK

注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例，了解如何进行设置和运行。


import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.applicationautoscaling.ApplicationAutoScalingClient;
import software.amazon.awssdk.services.applicationautoscaling.model.ApplicationAutoScalingException;
import software.amazon.awssdk.services.applicationautoscaling.model.DeleteScalingPolicyRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DeregisterScalableTargetRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.ScalableDimension;
import software.amazon.awssdk.services.applicationautoscaling.model.ServiceNamespace;

/**
 * Before running this Java V2 code example, set up your development environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */

public class DisableDynamoDBAutoscaling {
    public static void main(String[] args) {
        final String usage = """

            Usage:
               <tableId> <policyName>\s

            Where:
               tableId - The table Id value (for example, table/Music).\s
               policyName - The name of the policy (for example, $Music5-scaling-policy). 
        
            """;
        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        ApplicationAutoScalingClient appAutoScalingClient = ApplicationAutoScalingClient.builder()
            .region(Region.US_EAST_1)
            .build();

        ServiceNamespace ns = ServiceNamespace.DYNAMODB;
        ScalableDimension tableWCUs = ScalableDimension.DYNAMODB_TABLE_WRITE_CAPACITY_UNITS;
        String tableId = args[0];
        String policyName = args[1];

        deletePolicy(appAutoScalingClient, policyName, tableWCUs, ns, tableId);
        verifyScalingPolicies(appAutoScalingClient, tableId, ns, tableWCUs);
        deregisterScalableTarget(appAutoScalingClient, tableId, ns, tableWCUs);
        verifyTarget(appAutoScalingClient, tableId, ns, tableWCUs);
    }

    public static void deletePolicy(ApplicationAutoScalingClient appAutoScalingClient, String policyName, ScalableDimension tableWCUs, ServiceNamespace ns, String tableId) {
        try {
            DeleteScalingPolicyRequest delSPRequest = DeleteScalingPolicyRequest.builder()
                .policyName(policyName)
                .scalableDimension(tableWCUs)
                .serviceNamespace(ns)
                .resourceId(tableId)
                .build();

            appAutoScalingClient.deleteScalingPolicy(delSPRequest);
            System.out.println(policyName +" was deleted successfully.");

        } catch (ApplicationAutoScalingException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
    }

    // Verify that the scaling policy was deleted
    public static void verifyScalingPolicies(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        DescribeScalingPoliciesRequest dscRequest = DescribeScalingPoliciesRequest.builder()
            .scalableDimension(tableWCUs)
            .serviceNamespace(ns)
            .resourceId(tableId)
            .build();

        DescribeScalingPoliciesResponse response = appAutoScalingClient.describeScalingPolicies(dscRequest);
        System.out.println("DescribeScalableTargets result: ");
        System.out.println(response);
    }

    public static void deregisterScalableTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        try {
            DeregisterScalableTargetRequest targetRequest = DeregisterScalableTargetRequest.builder()
                .scalableDimension(tableWCUs)
                .serviceNamespace(ns)
                .resourceId(tableId)
                .build();

            appAutoScalingClient.deregisterScalableTarget(targetRequest);
            System.out.println("The scalable target was deregistered.");

        } catch (ApplicationAutoScalingException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
    }

    public static void verifyTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        DescribeScalableTargetsRequest dscRequest = DescribeScalableTargetsRequest.builder()
            .scalableDimension(tableWCUs)
            .serviceNamespace(ns)
            .resourceIds(tableId)
            .build();

        DescribeScalableTargetsResponse response = appAutoScalingClient.describeScalableTargets(dscRequest);
        System.out.println("DescribeScalableTargets result: ");
        System.out.println(response);
    }
}

有关 API 的详细信息，请参阅 Amazon SDK for Java 2.x API 参考DeleteScalingPolicy中的。

以下代码示例演示了如何使用 RegisterScalableTarget。

适用于 Java 2.x 的 SDK

注意

还有更多相关信息 GitHub。在 Amazon 代码示例存储库中查找完整示例，了解如何进行设置和运行。


import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.applicationautoscaling.ApplicationAutoScalingClient;
import software.amazon.awssdk.services.applicationautoscaling.model.ApplicationAutoScalingException;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalableTargetsResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.DescribeScalingPoliciesResponse;
import software.amazon.awssdk.services.applicationautoscaling.model.PolicyType;
import software.amazon.awssdk.services.applicationautoscaling.model.PredefinedMetricSpecification;
import software.amazon.awssdk.services.applicationautoscaling.model.PutScalingPolicyRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.RegisterScalableTargetRequest;
import software.amazon.awssdk.services.applicationautoscaling.model.ScalingPolicy;
import software.amazon.awssdk.services.applicationautoscaling.model.ServiceNamespace;
import software.amazon.awssdk.services.applicationautoscaling.model.ScalableDimension;
import software.amazon.awssdk.services.applicationautoscaling.model.MetricType;
import software.amazon.awssdk.services.applicationautoscaling.model.TargetTrackingScalingPolicyConfiguration;
import java.util.List;

/**
 * Before running this Java V2 code example, set up your development environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class EnableDynamoDBAutoscaling {
    public static void main(String[] args) {
        final String usage = """

            Usage:
               <tableId> <roleARN> <policyName>\s

            Where:
               tableId - The table Id value (for example, table/Music).
               roleARN - The ARN of the role that has ApplicationAutoScaling permissions.
               policyName - The name of the policy to create.
               
            """;

        if (args.length != 3) {
            System.out.println(usage);
            System.exit(1);
        }

        System.out.println("This example registers an Amazon DynamoDB table, which is the resource to scale.");
        String tableId = args[0];
        String roleARN = args[1];
        String policyName = args[2];
        ServiceNamespace ns = ServiceNamespace.DYNAMODB;
        ScalableDimension tableWCUs = ScalableDimension.DYNAMODB_TABLE_WRITE_CAPACITY_UNITS;
        ApplicationAutoScalingClient appAutoScalingClient = ApplicationAutoScalingClient.builder()
            .region(Region.US_EAST_1)
            .build();

        registerScalableTarget(appAutoScalingClient, tableId, roleARN, ns, tableWCUs);
        verifyTarget(appAutoScalingClient, tableId, ns, tableWCUs);
        configureScalingPolicy(appAutoScalingClient, tableId, ns, tableWCUs, policyName);
    }

    public static void registerScalableTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, String roleARN, ServiceNamespace ns, ScalableDimension tableWCUs) {
        try {
            RegisterScalableTargetRequest targetRequest = RegisterScalableTargetRequest.builder()
                .serviceNamespace(ns)
                .scalableDimension(tableWCUs)
                .resourceId(tableId)
                .roleARN(roleARN)
                .minCapacity(5)
                .maxCapacity(10)
                .build();

            appAutoScalingClient.registerScalableTarget(targetRequest);
            System.out.println("You have registered " + tableId);

        } catch (ApplicationAutoScalingException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
    }

    // Verify that the target was created.
    public static void verifyTarget(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs) {
        DescribeScalableTargetsRequest dscRequest = DescribeScalableTargetsRequest.builder()
            .scalableDimension(tableWCUs)
            .serviceNamespace(ns)
            .resourceIds(tableId)
            .build();

        DescribeScalableTargetsResponse response = appAutoScalingClient.describeScalableTargets(dscRequest);
        System.out.println("DescribeScalableTargets result: ");
        System.out.println(response);
    }

    // Configure a scaling policy.
    public static void configureScalingPolicy(ApplicationAutoScalingClient appAutoScalingClient, String tableId, ServiceNamespace ns, ScalableDimension tableWCUs, String policyName) {
        // Check if the policy exists before creating a new one.
        DescribeScalingPoliciesResponse describeScalingPoliciesResponse = appAutoScalingClient.describeScalingPolicies(DescribeScalingPoliciesRequest.builder()
            .serviceNamespace(ns)
            .resourceId(tableId)
            .scalableDimension(tableWCUs)
            .build());

        if (!describeScalingPoliciesResponse.scalingPolicies().isEmpty()) {
            // If policies exist, consider updating an existing policy instead of creating a new one.
            System.out.println("Policy already exists. Consider updating it instead.");
            List<ScalingPolicy> polList = describeScalingPoliciesResponse.scalingPolicies();
            for (ScalingPolicy pol : polList) {
                System.out.println("Policy name:" +pol.policyName());
            }
        } else {
            // If no policies exist, proceed with creating a new policy.
            PredefinedMetricSpecification specification = PredefinedMetricSpecification.builder()
                .predefinedMetricType(MetricType.DYNAMO_DB_WRITE_CAPACITY_UTILIZATION)
                .build();

            TargetTrackingScalingPolicyConfiguration policyConfiguration = TargetTrackingScalingPolicyConfiguration.builder()
                .predefinedMetricSpecification(specification)
                .targetValue(50.0)
                .scaleInCooldown(60)
                .scaleOutCooldown(60)
                .build();

            PutScalingPolicyRequest putScalingPolicyRequest = PutScalingPolicyRequest.builder()
                .targetTrackingScalingPolicyConfiguration(policyConfiguration)
                .serviceNamespace(ns)
                .scalableDimension(tableWCUs)
                .resourceId(tableId)
                .policyName(policyName)
                .policyType(PolicyType.TARGET_TRACKING_SCALING)
                .build();

            try {
                appAutoScalingClient.putScalingPolicy(putScalingPolicyRequest);
                System.out.println("You have successfully created a scaling policy for an Application Auto Scaling scalable target");
            } catch (ApplicationAutoScalingException e) {
                System.err.println("Error: " + e.awsErrorDetails().errorMessage());
            }
        }
    }
}

有关 API 的详细信息，请参阅 Amazon SDK for Java 2.x API 参考RegisterScalableTarget中的。

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