"transfer-log" RollingFile Appender

This appender manages file transfer logs with automatic file rotation.

Configuration example:

<RollingFile name="transfer-log" fileName="logs/transfers.log" filePattern="logs/transfers-%d{yyyy-MM-dd}.log">
    <ThresholdFilter level="INFO"/>
    <PatternLayout pattern="%d %-5p %m%n"/>
    <Policies>
        <SizeBasedTriggeringPolicy size="1000KB"/>
    </Policies>
    <DefaultRolloverStrategy max="100"/>
</RollingFile>

Example Log :

2025-02-06 15:28:15,342 INFO  a9d4ff0b-c88c-4291-b11d-6f9470666f9b Upload ready from my-user to my-user. Document name: /seattle.jpg, size: 191307

Log details:

1. 2025-02-06 15:28:15,342 : Date and time of the log
2. INFO : Log level
3. a9d4ff0b-c88c-4291-b11d-6f9470666f9b : User session identifier (from MDC)
4. Upload ready from my-user to my-user. Document name: /seattle.jpg, size: 191307 : Log message

This log is associated with the "Transfer Log" extension. It will not be filled without the extention being activated in the application.

Basic Configuration

• Name: transfer-log
• Output file: logs/transfers.log
• Archive file pattern: logs/transfers-[DATE].log

Log Format

The pattern %d %-5p %m%n defines the following format:

• %d : Log date and time
• %-5p : Log level (DEBUG, INFO, ERROR...) aligned to 5 characters
• %m : Log message
• %n : Line break

Rotation Policy

• SizeBasedTriggeringPolicy: 1000KB (1MB) per file
• DefaultRolloverStrategy: Maximum 100 archive files
• Rotation creates a new file when:
  • Current file reaches 1MB
  • A new day begins (based on date pattern)

Filter

• ThresholdFilter: Minimum level INFO
• Only messages of level INFO or higher (WARN, ERROR, FATAL) will be recorded
• DEBUG level messages will be ignored
• Minimalist format particularly suitable for:
  • File transfer operations monitoring
  • Quick transfer event analysis
  • Maintaining substantial history (100 files)

References

• Log4j2 RollingFile Appender