small fix - proper log4j MDC test pattern
MODIFY
instrumentation/log4j/log4j-2-testing/src/main/resources/log4j2-test.xml
instrumentation/log4j/log4j-2-testing/src/main/resources/log4j2-test.xml
<Configuration status="WARN" packages="com.example.appender">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
- <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} traceId: %X{traceId} spanId: %X{spanId} - %msg%n" />
+ <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} traceId: %X{trace_id} spanId: %X{span_id} flags: %X{trace_flags} - %msg%n" />
</Console>
<ListAppender name="ListAppender" />
</Appenders>

small fix - proper log4j MDC test pattern (#3218)