기계 번역으로 제공되는 번역입니다. 제공된 번역과 원본 영어의 내용이 상충하는 경우에는 영어 버전이 우선합니다.

# 를 사용하여 SDK 지표를 콘솔로 출력 AWS SDK for Java 2.x
<a name="metric-pub-impl-logging"></a>

`[LoggingMetricPublisher](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/metrics/LoggingMetricPublisher.html)` 구현은 지표를 애플리케이션의 콘솔 또는 로그 파일에 직접 출력합니다. 이 접근 방식은 Amazon CloudWatch와 같은 외부 서비스 없이 SDK가 수집하는 지표를 개발, 디버깅 및 이해하는 데 적합합니다.

`CloudWatchMetricPublisher` 및 `EmfMetricLoggingPublisher`와 달리 `LoggingMetricPublisher`는 지연이나 외부 종속성 없이 즉각적인 출력을 제공합니다. 따라서 로컬 개발 및 문제 해결 시나리오에 적합합니다.

## LoggingMetricPublisher를 사용해야 하는 경우
<a name="logging-metric-publisher-when-to-use"></a>

다음 작업 시 `LoggingMetricPublisher`를 사용합니다.
+ 개발 중 지표 수집 디버그
+ SDK가 작업에 대해 수집하는 지표 이해
+ 로컬 방식으로 성능 문제 해결
+ 외부 서비스 종속성 없이 지표 수집 테스트
+ 콘솔 또는 로그 파일에서 지표 즉시 보기

**참고**  
`LoggingMetricPublisher`는 영구 지표 스토리지 및 분석 기능이 필요한 프로덕션 환경에는 권장되지 않습니다.

## 지표용 콘솔 로깅 설정
<a name="logging-metric-publisher-setup"></a>

`LoggingMetricPublisher` 출력을 보려면 `INFO` 레벨 메시지를 표시하도록 로깅 프레임워크를 구성합니다. 다음 `log4j2.xml` 구성을 사용하면 지표가 콘솔에 표시됩니다.

```
<?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>
```

이 구성은 SDK가 `INFO` 레벨의 콘솔에 지표를 출력하도록 지시합니다. `LoggingMetricPublisher` 로거 구성을 사용하면 루트 로거가 `WARN` 또는 `ERROR` 등의 상위 수준을 사용하더라도 지표 출력이 나타납니다.

## 서비스 클라이언트에 대한 콘솔 지표 사용
<a name="logging-metric-publisher-basic-usage"></a>

다음 예제에서는 `LoggingMetricPublisher`를 만들고 Amazon Simple Storage Service 클라이언트와 함께 사용하는 방법을 보여줍니다.

```
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();
```

## 지표 출력 형식 선택
<a name="logging-metric-publisher-formatting-options"></a>

`LoggingMetricPublisher`에서 지원되는 2가지 출력 형식:
+ **PLAIN 형식(기본값):** 지표를 압축된 한 줄 항목으로 출력합니다.
+ **PRETTY 형식:** 사람이 읽을 수 있는 여러 줄 형식으로 지표를 출력합니다.

다음 예제에서는 개발 중에 읽기 쉽도록 PRETTY 형식을 사용하는 방법을 보여줍니다.

```
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();
```

## 전체 예제
<a name="logging-metric-publisher-complete-example"></a>

다음의 예제는 2가지 방식으로 `LoggingMetricPublisher`를 사용하는 쿼리를 보여줍니다.
+ 서비스 클라이언트 수준인 경우
+ 단일 요청인 경우

```
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();
    }
}
```

코드는 콘솔에 다음을 로그합니다.

```
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.
```

### 예제용 추가 아티팩트
<a name="logging-metric-publisher-complete-example-artifacts"></a>

Maven `pom.xml` 파일

```
<?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` 구성 파일

```
<?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>
```

지표에는 애플리케이션의 AWS API 사용 패턴을 이해하는 데 도움이 되는 타이밍 정보, 서비스 세부 정보, 작업 이름 및 HTTP 상태 코드가 포함됩니다.

## 다음 단계
<a name="logging-metric-publisher-next-steps"></a>

개발 및 디버깅에 `LoggingMetricPublisher`를 사용한 후 프로덕션 환경에 대해 다음 옵션을 고려합니다.
+ 장기 실행 애플리케이션의 경우 [CloudWatchMetricPublisher](metric-pub-impl-cwmp.md)를 사용하여 분석 및 알림용으로 Amazon CloudWatch에 지표를 전송합니다.
+  AWS Lambda 함수의 경우 [EmfMetricLoggingPublisher](metric-pub-impl-emf.md)를 사용하여 CloudWatch 임베디드 지표 형식으로 지표 게시