Logging

HestiaStore uses slf4j for internal logging. So you should include your preferred logging library like logback, log4j, or another with a bridge to slf4j. In case you use log4j, look at the example configuration:

Example configuration File for log4j

Bellow is the example Log4j2 configuration used in HestiaStore:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="INFO">
  <Appenders>

    <Console name="Console" target="SYSTEM_OUT">
      <PatternLayout
          pattern="%style{%d{ISO8601}}{white} %highlight{%-5level }[%style{%t}{bright,blue}] %style{%-C{1.mv}}{bright,yellow}: %msg%n%throwable" />
    </Console>

    <Console name="indexAppender" target="SYSTEM_OUT">
      <PatternLayout
          pattern="%style{%d{ISO8601}}{white} %highlight{%-5level }[%style{%t}{bright,blue}] index='%style{%X{index.name}}{magenta}' %style{%-C{1.mv}}{bright,yellow}: %msg%n%throwable" />
    </Console>

  </Appenders>
  <Loggers>
    <logger name="org.hestiastore.index" level="DEBUG" additivity="false">
      <appender-ref ref="indexAppender" />
    </logger>
    <Root level="DEBUG">
      <AppenderRef ref="Console"/>
    </Root>
  </Loggers>
</Configuration>

this example will produce logs look like this:

Log Appenders

• Console (default): Used by all components not explicitly assigned a logger. Outputs time, level, thread, and class name.
• indexAppender: Specifically configured for org.hestiastore.index, outputs additional context (index.name) for disambiguating messages from different index instances.

Customizing Logging Levels

You can control verbosity by modifying the <logger> or <Root> levels:

• ERROR, WARN, INFO, DEBUG, or TRACE
• For example, to suppress general debug logs:

<Root level="INFO">

Disabling Index Logs

If you want to disable index-specific logging entirely, remove or comment out the org.hestiastore.index logger section. Alternatively log level for package could be set to "ERROR".

Recommendations

• Use DEBUG during development or troubleshooting.
• Switch to INFO or WARN in production to reduce log noise.
• Ensure you clear MDC values (ThreadContext.clearAll()) in thread pools to prevent memory leaks or incorrect context reuse.

Logging Implementation

The indexAppender uses a mapped diagnostic context (MDC) value index.name, which should be set programmatically:

ThreadContext.put("index.name", "userIndex");

This allows the log output to include which index instance the message is referring to, aiding in debugging concurrent access or behavior across multiple indexes.