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使用AWS SDK for Java 2.x 从长时间运行的应用程序发布 SDK 指标

由于 CloudWatchMetricPublisher 实施会聚合指标并定期将指标上传到 Amazon CloudWatch，但存在延迟，因此该实施的使用非常适合长时间运行的应用程序。

指标发布者的默认设置可以更大限度地减少内存使用量和 CloudWatch 成本，同时仍能为指标数据提供一定数量的有用洞察。

设置

先完成以下步骤，然后才能使用 CloudWatchMetricPublisher 来启用和使用指标。

步骤 1：添加所需的依赖项

将项目依赖项（例如，在您的 pom.xml 或 build.gradle 文件中）配置为使用适用于 Java 的 AWS SDK 版本 2.14.0 或更高版本。

在项目的依赖项中包括 artifactId cloudwatch-metric-publisher，并使用版本号 2.14.0 或更高版本号。

例如：

<project>
  <dependencyManagement>
   <dependencies>
      <dependency>
        <groupId>software.amazon.awssdk</groupId>
        <artifactId>bom</artifactId>
        <version>2.30.11</version>  <!-- Navigate the link to see the latest version. -->
        <type>pom</type>
        <scope>import</scope>
      </dependency>
   </dependencies>
  </dependencyManagement>
  <dependencies>
   <dependency>
      <groupId>software.amazon.awssdk</groupId>
      <artifactId>cloudwatch-metric-publisher</artifactId>
   </dependency>
  </dependencies>
</project>

步骤 2：配置所需的权限

为指标发布者使用的 IAM 身份启用 cloudwatch:PutMetricData 权限，以允许适用于 Java 的 SDK 编写指标。

为特定请求启用指标

以下类演示如何为向 Amazon DynamoDB 发出的请求启用 CloudWatch 指标发布者。该类使用默认的指标发布者配置。

import software.amazon.awssdk.metrics.MetricPublisher;
import software.amazon.awssdk.metrics.publishers.cloudwatch.CloudWatchMetricPublisher;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.ListTablesRequest;

public class DefaultConfigForRequest {
    // Use one MetricPublisher for your application. It can be used with requests or service clients.
    static MetricPublisher metricsPub = CloudWatchMetricPublisher.create();

    public static void main(String[] args) {
        DynamoDbClient ddb = DynamoDbClient.create();
        // Publish metrics the for ListTables operation.
        ddb.listTables(ListTablesRequest.builder()
            .overrideConfiguration(c -> c.addMetricPublisher(metricsPub))
            .build());

        // Perform more work in your application.

        // A MetricsPublisher has its own lifecycle independent of any service client or request that uses it.
        // If you no longer need the publisher, close it to free up resources.
        metricsPub.close();  // All metrics stored in memory are flushed to CloudWatch.

        // Perform more work with the DynamoDbClient instance without publishing metrics.
        // Close the service client when you no longer need it.
        ddb.close();
    }
}

为特定服务客户端启用摘要指标

以下代码段演示如何为服务客户端启用采用默认设置的 CloudWatch 指标发布者。

MetricPublisher metricsPub = CloudWatchMetricPublisher.create();

DynamoDbClient ddb = DynamoDbClient.builder()
          .overrideConfiguration(c -> c.addMetricPublisher(metricsPub))
          .build();

自定义 CloudWatch 指标发布者

以下类演示如何为特定服务客户端的指标发布者设置自定义配置。自定义设置包括加载特定的配置文件、指定指标发布者发送请求时所在的 AWS 区域，以及自定义发布者向 CloudWatch 发送指标的频率。

import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.core.metrics.CoreMetric;
import software.amazon.awssdk.metrics.MetricPublisher;
import software.amazon.awssdk.metrics.publishers.cloudwatch.CloudWatchMetricPublisher;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatch.CloudWatchAsyncClient;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;

import java.time.Duration;

public class CustomConfigForDDBClient {
    // Use one MetricPublisher for your application. It can be used with requests or service clients.
    static MetricPublisher metricsPub = CloudWatchMetricPublisher.builder()
        .cloudWatchClient(CloudWatchAsyncClient.builder()
            .region(Region.US_WEST_2)
            .credentialsProvider(ProfileCredentialsProvider.create("cloudwatch"))
            .build())
        .uploadFrequency(Duration.ofMinutes(5))
        .maximumCallsPerUpload(100)
        .namespace("ExampleSDKV2Metrics")
        .detailedMetrics(CoreMetric.API_CALL_DURATION)
        .build();

    public static void main(String[] args) {
        DynamoDbClient ddb = DynamoDbClient.builder()
            .overrideConfiguration(c -> c.addMetricPublisher(metricsPub))
            .build();
        // Publish metrics for DynamoDB operations.
        ddb.listTables();
        ddb.describeEndpoints();
        ddb.describeLimits();
        // Perform more work in your application.

        // A MetricsPublisher has its own lifecycle independent of any service client or request that uses it.
        // If you no longer need the publisher, close it to free up resources.
        metricsPub.close();  // All metrics stored in memory are flushed to CloudWatch.


        // Perform more work with the DynamoDbClient instance without publishing metrics.
        // Close the service client when you no longer need it.
        ddb.close();
    }
}

上一个代码段中显示的自定义设置具有以下效果。

后续步骤：如果您也在使用 Lambda 函数，请参阅为 AWS Lambda 函数发布 SDK 指标，了解基于 EMF 的指标发布。