Log4j2 SDK v2

Available in Classic and VPC

In log4j2 SDK v2, it describes how to use log4j2 SDK v2, which is provided by Effective Log Search & Analytics 2.0 service.

The following describes how to use SDK.

1. Preparation
2. Add dependency
3. Set basic appender
4. Set AsyncAppender
5. Use SDK

1. Preparation

The following describes the preparations for installing log4j2 SDK.

1. In NAVER Cloud Platform's console, Create project.
2. Check the txtToken value in Project detail page.
3. Download log4j2 SDK.

2. Add dependency

The following describes how to install log4j2 SDK v2.

1. Unzip the downloaded SDK file.

2. Add dependency to the pom.xml file as follows:

   • Add directories of core module(nelo2-java-sdk-core-1.6.6.jar) and log4j2 module(nelo2-java-sdk-log4j2-2.8.5.jar) to <systemPath>

    <dependencies>
           <dependency>
               <groupId>nelo2-java-sdk-core</groupId>
               <artifactId>nelo2-java-sdk-core</artifactId>
               <version>1.6.6</version>
               <scope>system</scope>
               <systemPath>/nelo2-java-sdk-core-1.6.6.jar</systemPath>
           </dependency>
           <dependency>
               <groupId>nelo2-java-sdk</groupId>
               <artifactId>nelo2-java-sdk-log4j2</artifactId>
               <version>2.8.5</version>
               <scope>system</scope>
               <systemPath>/nelo2-java-sdk-log4j2-2.8.5.jar</systemPath>
           </dependency>
           <dependency>
               <groupId>org.apache.logging.log4j</groupId>
               <artifactId>log4j-api</artifactId>
               <version>2.8.2</version>
           </dependency>
           <dependency>
               <groupId>org.apache.logging.log4j</groupId>
               <artifactId>log4j-core</artifactId>
               <version>2.8.2</version>
           </dependency>
           <dependency>
               <groupId>org.apache.logging.log4j</groupId>
               <artifactId>log4j-slf4j-impl</artifactId>
               <version>2.8.2</version>
           </dependency>
           <dependency>
               <groupId>org.apache.thrift</groupId>
               <artifactId>libthrift</artifactId>
               <version>0.9.3</version>
           </dependency>
           <dependency>
               <groupId>org.apache.httpcomponents</groupId>
               <artifactId>httpclient</artifactId>
               <version>4.2.6</version>
           </dependency>
           <dependency>
               <groupId>com.fasterxml.jackson.core</groupId>
               <artifactId>jackson-databind</artifactId>
               <version>2.3.1</version>
           </dependency>
   </dependencies>
   

3. Set basic appender

The following describes how to set the basic appender.

• File name: log4j2.xml

Enter configuration as the following example:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN" shutDownHook="disable">
    <Appenders>
        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>
        <ThriftAppender>
            <name>nelo</name>
            <collectorUrl>COLLECTOR_HOST</collectorUrl>
            <port>COLLECTOR_PORT</port>
            <projectName>PROJECT_ID</projectName>
            <version>PROJECT_VERSION</version>
            <logType>LOG_TYPE</logType>
            <logSource>LOG_SOURCE</logSource>
        </ThriftAppender>
        <HttpAppender>
            <name>http</name>
            <collectorUrl>COLLECTOR_HOST</collectorUrl>
            <port>COLLECTOR_PORT</port>
            <projectName>PROJECT_ID</projectName>
            <version>PROJECT_VERSION</version>
            <logType>LOG_TYPE</logType>
            <logSource>LOG_SOURCE</logSource>
        </HttpAppender>
    </Appenders>
    <Loggers>
        <Logger name="nelo" level="error" additivity="false">
            <AppenderRef ref="nelo"/>
            <AppenderRef ref="console"/>
        </Logger>
        <Root level="warn">
            <AppenderRef ref="nelo"/>
            <AppenderRef ref="console"/>
        </Root>
    </Loggers>
</Configuration>

The following describes each setting option.

Bulk and single modes

NELO2 log4j2 SDK supports the single mode, where logs are transferred one by one, and the bulk mode, where logs are transferred in bulk. You can select bulk or single mode by setting isBulkEnabled to true or false in xml appender settings (Default: true(bulk mode)).
Following the protocol, note the following performance indicator:

• The throughput when a 1 kb-sized log is transferred in a single thread for a minute
  • thrift
    • Single mode: 2636.00 logs/sec
    • Bulk mode: 6369.10 logs/sec
  • http
    • Single mode: 583.36 logs/sec
    • Bulk mode: 4618.90 logs/sec

4. Set AsyncAppender

You can execute the actual log transfer task in a separate thread using AsyncAppender, supported by log4j2, in addition to the appender by default.

Set AsyncAppender referring to the following example.

<example>

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN" shutDownHook="disable">
    <Appenders>
        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>
        <ThriftAppender>
            <name>nelo</name>
            <collectorUrl>COLLECTOR_HOST</collectorUrl>
            <port>COLLECTOR_PORT</port>
            <projectName>PROJECT_ID</projectName>
            <version>PROJECT_VERSION</version>
            <logType>LOG_TYPE</logType>
            <logSource>LOG_SOURCE</logSource>
        </ThriftAppender>
        <HttpAppender>
            <name>http</name>
            <collectorUrl>COLLECTOR_HOST</collectorUrl>
            <port>COLLECTOR_PORT</port>
            <projectName>PROJECT_ID</projectName>
            <version>PROJECT_VERSION</version>
            <logType>LOG_TYPE</logType>
            <logSource>LOG_SOURCE</logSource>
        </HttpAppender>
        <Async name="async">
            <AppenderRef ref="nelo"/>
            <includeLocation>true</includeLocation>
        </Async>
    </Appenders>
    <Loggers>
        <Logger name="nelo" level="error" additivity="false">
            <AppenderRef ref="async"/>
            <AppenderRef ref="console"/>
        </Logger>
        <Root level="warn">
            <AppenderRef ref="nelo"/>
            <AppenderRef ref="console"/>
        </Root>
    </Loggers>
</Configuration>

5. Use SDK

Refer to the following actual codes that use Effective Log Search & Analytics 2.0 log4j2 SDK and transfer logs to the projects.

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

private static final Logger logger = LoggerFactory.getLogger("nelo");
...
    logger.debug("Effective Log Search & Analytics log4j2 SDK Debug Message");
    try {
        String npe = null;
        npe.toString();
    } catch(Exception e) {
        logger.error("Effective Log Search & Analytics log4j2 SDK Exception", e);
    }

Troubleshooting log4j2 SDK v2

Check potential problems and the solutions in relation to log4j2 SDK v2.

When logs are transferred to the Effective Log Search & Analytics 2.0 server but you cannot view them from the web

When you view the transferred logs from the web, please take the following measures:

1. Check if the projectName is correct when there is no error in the result message after transferring the logs to Effective Log Search & Analytics 2.0's collecting server.
2. Check if the actual error date is transferred.
   • Check if the following transfer log is exported after setting the Effective Log Search & Analytics 2.0 NELO appender's debug attribute to true in the configuration file (log4j.xml).

  <!-- define nelo appender -->
  <ThriftAppender>
      <name>nelo</name>
      <collectorUrl>COLLECTOR_HOST</collectorUrl>
      <port>COLLECTOR_PORT</port>
      <projectName>PROJECT_ID</projectName>
      <version>PROJECT_VERSION</version>
      <logType>LOG_TYPE</logType>
      <logSource>LOG_SOURCE</logSource>
      <debug>true</debug>
  </ThriftAppender>

  [NELO2] Log Append : sent event, return value :
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