何时使用 LoggingMetricPublisher 为指标设置控制台日志为服务客户端启用控制台指标选择指标输出格式完整示例后续步骤

使用向控制台输出 SDK 指标 AWS SDK for Java 2.x

该LoggingMetricPublisher实现将指标直接输出到应用程序的控制台或日志文件。这种方法非常适合开发、调试和了解 SDK 收集的指标，而无需像 Amazon 这样的外部服务 CloudWatch。

与CloudWatchMetricPublisher和不同EmfMetricLoggingPublisher，LoggingMetricPublisher它提供即时输出，没有延迟或外部依赖。这使其非常适合本地开发和故障排除场景。

何时使用 LoggingMetricPublisher

在需要执行以下操作时使用 LoggingMetricPublisher：

在开发过程中调试指标收集
了解 SDK 为您的运营收集了哪些指标
对本地性能问题进行故障排除
不依赖外部服务的测试指标收集
立即在控制台或日志文件中查看指标

注意

LoggingMetricPublisher不建议在需要持久指标存储和分析功能的生产环境中使用。

为指标设置控制台日志

要查看LoggingMetricPublisher输出，请将您的日志框架配置为显示INFO级别消息。以下log4j2.xml配置可确保指标显示在您的控制台中：


<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Appenders>
        <Console name="ConsoleAppender" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>
    </Appenders>
    <Loggers>
        <Root level="INFO">
            <AppenderRef ref="ConsoleAppender"/>
        </Root>
        <!-- Ensure LoggingMetricPublisher output appears. -->
        <Logger name="software.amazon.awssdk.metrics.LoggingMetricPublisher" level="INFO" />
    </Loggers>
</Configuration>

此配置指示 SDK 在INFO级别将指标输出到您的控制台。LoggingMetricPublisher记录器配置可确保即使您的根记录器使用更高的级别（如或），也能显示指标输出。WARN ERROR

为服务客户端启用控制台指标

以下示例说明如何创建并将其与 Amazon 简单存储服务客户端一起使用：LoggingMetricPublisher


import software.amazon.awssdk.metrics.LoggingMetricPublisher;
import software.amazon.awssdk.metrics.MetricPublisher;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;

// Create a LoggingMetricPublisher with default settings.
MetricPublisher metricPublisher = LoggingMetricPublisher.create();

// Add the publisher to your service client.
S3Client s3Client = S3Client.builder()
    .region(Region.US_EAST_1)
    .overrideConfiguration(config -> config.addMetricPublisher(metricPublisher))
    .build();

// Make requests - metrics will appear in your console.
s3Client.listBuckets();

// Clean up resources.
metricPublisher.close();
s3Client.close();

选择指标输出格式

LoggingMetricPublisher支持两种输出格式：

PL@@ AIN 格式（默认）：将指标输出为紧凑的单行条目
PRETTY 格式：以多行、人类可读的格式输出指标

以下示例说明了如何在开发过程中使用 PRETTY 格式以便于阅读：


import org.slf4j.event.Level;
import software.amazon.awssdk.metrics.LoggingMetricPublisher;

// Create a LoggingMetricPublisher with PRETTY format.
MetricPublisher prettyMetricPublisher = LoggingMetricPublisher.create(
    Level.INFO, 
    LoggingMetricPublisher.Format.PRETTY
);

// Use with your service client.
S3Client s3Client = S3Client.builder()
    .region(Region.US_EAST_1)
    .overrideConfiguration(config -> config.addMetricPublisher(prettyMetricPublisher))
    .build();

完整示例

以下示例演示LoggingMetricPublisher了两种使用方式：

在服务客户层面
对于单个请求


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.event.Level;
import software.amazon.awssdk.metrics.LoggingMetricPublisher;
import software.amazon.awssdk.metrics.MetricPublisher;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.ListBucketsRequest;
import software.amazon.awssdk.services.s3.model.ListBucketsResponse;

/**
 * Demonstrates how to use LoggingMetricPublisher with AWS S3 SDK for Java 2.x.
 * <p>
 * This demo focuses on the S3 listBuckets operation to show how metrics are collected
 * and logged to the console for development and debugging purposes.
 * <p>
 * LoggingMetricPublisher is ideal for:
 * - Development and debugging
 * - Console output for troubleshooting
 * - Understanding what metrics are being collected
 * - Testing metric collection without external dependencies
 */
public class S3LoggingMetricPublisherDemo {

    private static final Logger logger = LoggerFactory.getLogger(S3LoggingMetricPublisherDemo.class);

    public static void main(String[] args) {
        S3LoggingMetricPublisherDemo demo = new S3LoggingMetricPublisherDemo();
        demo.demonstrateUsage();
    }

    /**
     * Demonstrates basic usage with S3Client and metrics enabled at the client level.
     */
    private void demonstrateUsage() {

        // Create a LoggingMetricPublisher with default settings. The SDK logs metrics as text in a single line.
        // The default settings are equivalent to using `LoggingMetricPublisher.Format.PLAIN`.

        MetricPublisher metricPublisher = LoggingMetricPublisher.create();

        // Create an S3 client with metrics enabled.
        try (S3Client s3Client = S3Client.builder()
                .region(Region.US_EAST_1)
                .overrideConfiguration(config -> config.addMetricPublisher(metricPublisher))
                .build()) {

            // Make the listBuckets request - metrics will be logged to console.
            ListBucketsResponse response = s3Client.listBuckets(ListBucketsRequest.builder().build());

            // The next block shows the using a different LoggingMetricPublisher with a `PRETTY` format.
            // Since the metric publisher is added to the request using the `overrideConfiguration`, this formatting
            // applies only to the one request.
            try {
                s3Client.listBuckets(ListBucketsRequest.builder()
                        .overrideConfiguration(config -> config
                                .addMetricPublisher(LoggingMetricPublisher.create(
                                        Level.INFO, LoggingMetricPublisher.Format.PRETTY)))
                        .build());
            } catch (Exception e) {
                logger.info("Request failed with metrics logged: {}", e.getMessage());
            }
            logger.info("Found {} buckets in your AWS account.", response.buckets().size());

        } catch (Exception e) {
            logger.error("Error during S3 operation: {}", e.getMessage());
            logger.info("Note: This is expected if AWS credentials are not configured.");
        }

        // Close the metric publisher to flush any remaining metrics.
        metricPublisher.close();
    }
}

该代码将以下内容记录到控制台：


INFO  LoggingMetricPublisher - Metrics published: MetricCollection(name=ApiCall, metrics=[MetricRecord(metric=MarshallingDuration, value=PT0.005409792S), MetricRecord(metric=RetryCount, value=0), MetricRecord(metric=ApiCallSuccessful, value=true), MetricRecord(metric=OperationName, value=ListBuckets), MetricRecord(metric=EndpointResolveDuration, value=PT0.000068S), MetricRecord(metric=ApiCallDuration, value=PT0.163802958S), MetricRecord(metric=CredentialsFetchDuration, value=PT0.145686542S), MetricRecord(metric=ServiceEndpoint, value=https://s3.amazonaws.com), MetricRecord(metric=ServiceId, value=S3)], children=[MetricCollection(name=ApiCallAttempt, metrics=[MetricRecord(metric=TimeToFirstByte, value=PT0.138816S), MetricRecord(metric=SigningDuration, value=PT0.007803459S), MetricRecord(metric=ReadThroughput, value=165153.96002660287), MetricRecord(metric=ServiceCallDuration, value=PT0.138816S), MetricRecord(metric=AwsExtendedRequestId, value=e13Swj3uwn0qP1Oz+m7II5OGq7jf8xxT8H18iDfRBCQmDg+gU4ek91Xrsl8XxRLROlIzCAPQtsQF0DAAWOb8ntuKCzX2AJdj), MetricRecord(metric=HttpStatusCode, value=200), MetricRecord(metric=BackoffDelayDuration, value=PT0S), MetricRecord(metric=TimeToLastByte, value=PT0.148915667S), MetricRecord(metric=AwsRequestId, value=78AW9BM7SWR6YMGB)], children=[MetricCollection(name=HttpClient, metrics=[MetricRecord(metric=MaxConcurrency, value=50), MetricRecord(metric=AvailableConcurrency, value=0), MetricRecord(metric=LeasedConcurrency, value=1), MetricRecord(metric=ConcurrencyAcquireDuration, value=PT0.002623S), MetricRecord(metric=PendingConcurrencyAcquires, value=0), MetricRecord(metric=HttpClientName, value=Apache)], children=[])])])
INFO  LoggingMetricPublisher - [4e6f2bb5] ApiCall
INFO  LoggingMetricPublisher - [4e6f2bb5] ┌──────────────────────────────────────────┐
INFO  LoggingMetricPublisher - [4e6f2bb5] │ MarshallingDuration=PT0.000063S          │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ RetryCount=0                             │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ ApiCallSuccessful=true                   │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ OperationName=ListBuckets                │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ EndpointResolveDuration=PT0.000024375S   │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ ApiCallDuration=PT0.018463083S           │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ CredentialsFetchDuration=PT0.000022334S  │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ ServiceEndpoint=https://s3.amazonaws.com │
INFO  LoggingMetricPublisher - [4e6f2bb5] │ ServiceId=S3                             │
INFO  LoggingMetricPublisher - [4e6f2bb5] └──────────────────────────────────────────┘
INFO  LoggingMetricPublisher - [4e6f2bb5]     ApiCallAttempt
INFO  LoggingMetricPublisher - [4e6f2bb5]     ┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ TimeToFirstByte=PT0.0165575S                                                                                          │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ SigningDuration=PT0.000301125S                                                                                        │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ ReadThroughput=1195591.792850103                                                                                      │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ ServiceCallDuration=PT0.0165575S                                                                                      │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ AwsExtendedRequestId=3QI1eenRuokdszWqZBmBMDUmko6FlSmHkM+CUMNMeLor7gJml4D4lv6QXUZ1zWoTgG+tHbr6yo2vHdz4h1P8PDovvtMFRCeB │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ HttpStatusCode=200                                                                                                    │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ BackoffDelayDuration=PT0S                                                                                             │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ TimeToLastByte=PT0.017952625S                                                                                         │
INFO  LoggingMetricPublisher - [4e6f2bb5]     │ AwsRequestId=78AVFAF795AAWAXH                                                                                         │
INFO  LoggingMetricPublisher - [4e6f2bb5]     └───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
INFO  LoggingMetricPublisher - [4e6f2bb5]         HttpClient
INFO  LoggingMetricPublisher - [4e6f2bb5]         ┌───────────────────────────────────────┐
INFO  LoggingMetricPublisher - [4e6f2bb5]         │ MaxConcurrency=50                     │
INFO  LoggingMetricPublisher - [4e6f2bb5]         │ AvailableConcurrency=0                │
INFO  LoggingMetricPublisher - [4e6f2bb5]         │ LeasedConcurrency=1                   │
INFO  LoggingMetricPublisher - [4e6f2bb5]         │ ConcurrencyAcquireDuration=PT0.00004S │
INFO  LoggingMetricPublisher - [4e6f2bb5]         │ PendingConcurrencyAcquires=0          │
INFO  LoggingMetricPublisher - [4e6f2bb5]         │ HttpClientName=Apache                 │
INFO  LoggingMetricPublisher - [4e6f2bb5]         └───────────────────────────────────────┘
INFO  S3LoggingMetricPublisherDemo - Found 6 buckets in your AWS account.

Maven 文件 pom.xml


<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
         http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>s3-logging-metric-publisher-demo</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>

    <name>AWS S3 LoggingMetricPublisher Demo</name>
    <description>Demonstrates how to use LoggingMetricPublisher with AWS S3 SDK for Java 2.x</description>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <aws.java.sdk.version>2.31.66</aws.java.sdk.version>
        <log4j.version>2.24.3</log4j.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- AWS SDK BOM for dependency management -->
            <dependency>
                <groupId>software.amazon.awssdk</groupId>
                <artifactId>bom</artifactId>
                <version>${aws.java.sdk.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!-- Log4j BOM for logging dependency management -->
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-bom</artifactId>
                <version>${log4j.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <!-- AWS S3 SDK for demonstration -->
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>s3</artifactId>
        </dependency>

        <!-- Log4j2 SLF4J implementation -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j2-impl</artifactId>
        </dependency>

        <!-- Log4j2 Core -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.13.0</version>
                <configuration>
                    <source>17</source>
                    <target>17</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Log4j2.xml 配置文件


<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Appenders>
        <Console name="ConsoleAppender" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>
    </Appenders>
    <Loggers>
        <Root level="INFO">
            <AppenderRef ref="ConsoleAppender"/>
        </Root>
        <!-- Ensure LoggingMetricPublisher output appears. -->
        <Logger name="software.amazon.awssdk.metrics.LoggingMetricPublisher" level="INFO"/>
    </Loggers>
</Configuration>

这些指标包括计时信息、服务详细信息、操作名称和 HTTP 状态代码，可帮助您了解应用程序的 AWS API 使用模式。

后续步骤

在LoggingMetricPublisher用于开发和调试之后，请考虑生产环境中的以下选项：

对于长时间运行的应用程序，使用CloudWatchMetricPublisher向 Amazon 发送指标以 CloudWatch 供分析和提醒
对于 AWS Lambda 函数，使用EmfMetricLoggingPublisher以 CloudWatch 嵌入式指标格式发布指标

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文档惯例

Lambda 函数

指标参考