Logback AsyncAppender does not log context details

[shamoh]

Discussed in #1260

^{Originally posted by shamoh February 12, 2023}
I use TraceIDConverter to log request ID or ContextEntryConverter for additional information. But it does not work in case of AsyncAppender. Target appender is ConsoleAppender.

My configuration is:

<configuration scan="false" debug="false">
    <conversionRule conversionWord="traceId"
                    converterClass="kamon.instrumentation.logback.tools.TraceIDConverter"/>
    <conversionRule conversionWord="contextEntry"
                    converterClass="kamon.instrumentation.logback.tools.ContextEntryConverter"/>

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="net.logstash.logback.encoder.LoggingEventCompositeJsonEncoder">
            <providers>
                <timestamp/>
                <pattern>
                    <omitEmptyFields>true</omitEmptyFields>
                    <pattern>
                        {
                            "request-id": "%traceId",
                            "entry-component": "%contextEntry{entryComponent}",
                        }
                    </pattern>
                </pattern>
            </providers>
        </encoder>
    </appender>

    <appender name="ASYNC-STDOUT" class="ch.qos.logback.classic.AsyncAppender">
        <queueSize>8192</queueSize>
        <neverBlock>true</neverBlock>
        <discardingThreshold>25</discardingThreshold>

        <appender-ref ref="STDOUT"/>
    </appender>

    <logger name="com.example.my" level="INFO"/>

    <root level="INFO">
        <appender-ref ref="ASYNC-STDOUT"/> <!-- does NOT work -->
        <!-- OR -->
        <appender-ref ref="STDOUT"/>       <!-- it WORKS -->
    </root>
</configuration>

If I use STDOUT appender it correctly logs request-id and entry-component. While in case of ASYNC-STDOUT appender it does not log entry-component and request-id is undefined.

Documentation (https://kamon.io/docs/latest/instrumentation/logback/) says AsyncAppender is supported. Do I use wrong combination of appender and encoder?