Logback Configuration (RFC-27)

RFC-27 compliant static Logback configuration for Java services.

When to use this skill

• Setting up logging configuration for new Java services
• Reviewing or updating logback.xml configuration
• Configuring environment-specific logging
• Setting up log file rotation and retention
• Configuring appenders for different outputs (console, file, JSON)

Skill Contents

Sections

• When to use this skill (L24-L31)
• Quick Start (L52-L90)
• Configuration Structure (L91-L115)
• Appender Types (L116-L134)
• Environment Configuration (L135-L154)
• References (L155-L160)
• Related Rules (L161-L164)
• Related Skills (L165-L170)

Available Resources

📚 references/ - Detailed documentation

• configuration patterns

Quick Start

1. Create logback-spring.xml

Place in

src/main/resources/logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="30 seconds">
    <include resource="org/springframework/boot/logging/logback/defaults.xml"/>

    <!-- Console appender for local development -->
    <springProfile name="local">
        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
            <encoder>
                <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
            </encoder>
        </appender>
        <root level="INFO">
            <appender-ref ref="CONSOLE"/>
        </root>
    </springProfile>

    <!-- JSON appender for production -->
    <springProfile name="!local">
        <appender name="JSON" class="ch.qos.logback.core.ConsoleAppender">
            <encoder class="net.logstash.logback.encoder.LogstashEncoder"/>
        </appender>
        <root level="INFO">
            <appender-ref ref="JSON"/>
        </root>
    </springProfile>
</configuration>

2. Do NOT Commit logback.xml to Git

Per RFC-27,

logback.xml

logback-spring.xml

Configuration Structure

Required Elements

<configuration>

<appender>

<encoder>

<root>

Spring Profile Integration

Use

<springProfile>

<springProfile name="production">
    <!-- Production-specific config -->
</springProfile>

<springProfile name="!production">
    <!-- Non-production config -->
</springProfile>

Appender Types

ConsoleAppender

RollingFileAppender

AsyncAppender

Console Appender (Production)

<appender name="JSON" class="ch.qos.logback.core.ConsoleAppender">
    <encoder class="net.logstash.logback.encoder.LogstashEncoder">
        <includeMdcKeyName>traceId</includeMdcKeyName>
        <includeMdcKeyName>spanId</includeMdcKeyName>
    </encoder>
</appender>

Environment Configuration

Log Levels per Environment

local

development

staging

production

Logger Overrides

<!-- Reduce noise from specific libraries -->
<logger name="org.apache.kafka" level="WARN"/>
<logger name="org.springframework.web" level="INFO"/>
<logger name="com.bitso" level="DEBUG"/>

References

Related Rules

• java-structured-logs - Structured logging standards (RFC-34)

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