how to print mdc value in logback

Question

I'm not getting mdc value in logback

can you please help me

Java Code:

       String traceId = MDC.get(getJlgConfiguration().getTraceId());
        String sessionId = MDC.get(getJlgConfiguration().getSessionId());

Logback.xml

<configuration scan="true" scanPeriod="60" debug="true">

    <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
        <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} - %class{0}.%M %L, ole-session-id:%mdc{ole-session-id:-NONE}, jlg-trace-id:%mdc{jlg-trace-id:-NONE} - %msg%n
        </Pattern>
    </encoder>
    <root level="info">
        <appender-ref ref="CONSOLE"/>
    </root>
</configuration>

You snippet is get() ? You need to put (Key, Val) and then log and then remove. If you wanna format with your own layout, you'll need to know the key. See the sample on http://logback.qos.ch/manual/mdc.html — HoaPhan, Jun 04 '20 at 23:35

score 0 · Answer 1 · answered Jun 04 '20 at 13:11

0

You have to use %X instead of %mdc

%d{yyyy-MM-dd HH:mm:ss} - %class{0}.%M %L, ole-session-id:%X{ole-session-id:-NONE}, jlg-trace-id:%X{jlg-trace-id:-NONE} - %msg%n

Checkout the documentation for more information http://logback.qos.ch/manual/mdc.html

answered Jun 04 '20 at 13:11

Simon Martinelli

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Still am not getting value! if I use the above code – Aswad Shaik Jun 04 '20 at 13:49
I just see it now. Why do you use an Encoder and not an appender? And the pattern is not in the CONSOLE appender confugred – Simon Martinelli Jun 04 '20 at 14:52

score 0 · Answer 2 · answered Oct 20 '22 at 09:59

Maybe this answer can help, not able to put the values in the MDC

Basically if for example, you're using log4j as the impl underneath slf4j, then you would need log4j config (ConversionPattern) like:

<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
        <pattern>%-5p| %t | [ole-session-id:%X{ole-session-id:-NONE}, jlg-trace-id:%X{jlg-trace-id:-NONE}] | %logger{36} | %m %n</pattern>
    </encoder>
</appender>

how to print mdc value in logback

2 Answers2