[LOG4J2-1561] print expected mdc info to each line of the exception stacktrace

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 2.6.2
• Fix Version/s: 2.6.2
• Component/s: Core
• Labels: features

Environment

OS X EI Caption, Java 1.7

• Assignee: Unassigned
• Reporter: Zilong Song
• Created: 03/Sep/16 15:20
• Updated: 06/Mar/17 05:01
• Resolved: 06/Mar/17 05:01

Description

In some applications we need to append certain MDC information to each line of logs for a certain process, so that we can easily distinguish them from other logs, and do further analysis. But currently this information cannot be appended to any line of the stack trace, so it's hard to get the lines of the stack trace from a textual log file with massive lines of logs. This issue will append this information to each line of the stack trace.

An already known usage for this feature is that we can easily get all lines of log for a certain process when we set an ID before the process starts, including all lines of the stack trace.

Following is the code and configuration, and the output of it.

Test.main()

public static void main(String[] args) {
    final Logger logger = LogManager.getRootLogger();
    ThreadContext.put("proc_id", "1234567890");
    Exception exception = new Exception("sample exception");
    logger.info("an exception is logged", exception);
}

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" name="live-im">
    <Appenders>
        <Console name="console-log" target="SYSTEM_OUT">
            <PatternLayout pattern="%d %p [%t] %C{2} (%F:%L) - %m %X{proc_id}%n%cEx{proc_id}"/>
        </Console>
    </Appenders>
    <Loggers>
        <Root level="all">
            <AppenderRef ref="console-log"/>
        </Root>
    </Loggers>
</Configuration>

output

2016-09-03 22:56:56,721 INFO [main] pattern.Test (Test.java:17) - an exception is logged 1234567890
java.lang.Exception: sample exception 1234567890
	at org.apache.logging.log4j.core.pattern.Test.main(Test.java:16) [classes/:?] 1234567890
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_91] 1234567890
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_91] 1234567890
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_91] 1234567890
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_91] 1234567890
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) [idea_rt.jar:?] 1234567890

Issue Links

• Is contained by: LOG4J2-1838 Add support for appending common suffix to each line of throwable stack trace
• links to: GitHub Pull Request #38