[jira] [Commented] (LOG4J2-3330) Configurator.setLevel not fetching the correct LoggerContext

["Gary D. Gregory (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/LOG4J2-3330?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17474497#comment-17474497 ] 

Gary D. Gregory commented on LOG4J2-3330:
-----------------------------------------

The problems applies to the following APIs in {{{}org.apache.logging.log4j.core.config.Configurator{}}}:
 * setAllLevels(String, Level)
 * Configurator.setLevel(Map<String, Level>)
 * setLevel(String, Level)
 * setRootLevel(Level)

Fixing...

> Configurator.setLevel not fetching the correct LoggerContext
> ------------------------------------------------------------
>
>                 Key: LOG4J2-3330
>                 URL: https://issues.apache.org/jira/browse/LOG4J2-3330
>             Project: Log4j 2
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 2.17.1
>            Reporter: Mircea Lemnaru
>            Assignee: Gary D. Gregory
>            Priority: Major
>
> I needed to set the log level for a certain logger in the application and for that I tried using the following code:
> {{Configurator.setLevel(logger,level)}} but it did not seem to set the proper logging level.
> After looking over the source code I have noticed the following behaviour:
> Inside setLevel there is this line:
> {code:java}
> LoggerContext loggerContext = LoggerContext.getContext(false);{code}
> Which fetches the LoggerContext for the caller class.
> In turn , LoggerContext.getContext has the following content:
>  
> {code:java}
> public static LoggerContext getContext(final boolean currentContext)
> { return (LoggerContext) LogManager.getContext(currentContext); }
> {code}
>  
> Which delegates the context fetching to LogManager
> LogManager in turn get's the context by passing a hardcoded class name as the stack marker:
> {code:java}
> private static final String FQCN = LogManager.class.getName();{code}
> Because of this , the methods LoggerContext.getContext and LogManager.getContext behave differently in environments with multiple LoggerContexts and ClassLoaders
> Test: 
>  # Calling LoggerContext.getContext - returns LoggerContextA - corresponding to the classloader of LoggerContext because if we look at the stack trace:
> {code:java}
> getCallerClass:151, StackLocator (org.apache.logging.log4j.util)
> getCallerClass:70, StackLocatorUtil (org.apache.logging.log4j.util)
> getCallerClass:58, StackLocatorUtil (org.apache.logging.log4j.util)
> getContext:138, ClassLoaderContextSelector (org.apache.logging.log4j.core.selector)
> getContext:123, ClassLoaderContextSelector (org.apache.logging.log4j.core.selector)
> getContext:230, Log4jContextFactory (org.apache.logging.log4j.core.impl)
> getContext:47, Log4jContextFactory (org.apache.logging.log4j.core.impl)
> getContext:176, LogManager (org.apache.logging.log4j)
> getContext:231, LoggerContext (org.apache.logging.log4j.core) <---- returns this
> handle:24, LogLevelChangeHandler (com.ispring.log.event) <----- real caller class{code}
> Because of the fact that the context is fetched by providing the hardcoded FQCN which is LogManager ... getCallerClass(FQCN) will return LoggerContext instead of returning LogLevelChangeHandler ( the real caller )
> 2. Calling LogManager.getContext - returns LoggerContextB - corresponding to the classloader of LogLevelChangeHandler which is the correct behaviour since LogLevelChangeHandler is the class that is actually requesting the context.
> If we look at the stack trace:
> {code:java}
> getCallerClass:151, StackLocator (org.apache.logging.log4j.util)
> getCallerClass:70, StackLocatorUtil (org.apache.logging.log4j.util)
> getCallerClass:58, StackLocatorUtil (org.apache.logging.log4j.util)
> getContext:138, ClassLoaderContextSelector (org.apache.logging.log4j.core.selector)
> getContext:123, ClassLoaderContextSelector (org.apache.logging.log4j.core.selector)
> getContext:230, Log4jContextFactory (org.apache.logging.log4j.core.impl)
> getContext:47, Log4jContextFactory (org.apache.logging.log4j.core.impl)
> getContext:176, LogManager (org.apache.logging.log4j) <-- break point 
> handle:25, LogLevelChangeHandler (com.ispring.log.event) <--- the correct class to be returned{code}
> Because of the behaviour mentioned above , calling Configurator.setLevel doesn't have de desired effect in environments with multiple LoggerContexts ( webapp deployed in tomcat ) because it's setting the level one some LoggerContext which is not the one used by the application classes.



--
This message was sent by Atlassian Jira
(v8.20.1#820001)