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https://issues.apache.org/jira/browse/LOG4J2-2940?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17292341#comment-17292341
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Ralph Goers commented on LOG4J2-2940:
-------------------------------------
Adding support for SLF4J-2.0.0 is likely going to impact how this problem gets
solved so LOG4J2-2975 should be handled first.
> High CPU at Java 11 due to the use of StackWalker from
> StackLocator.getCallerClass
> ----------------------------------------------------------------------------------
>
> Key: LOG4J2-2940
> URL: https://issues.apache.org/jira/browse/LOG4J2-2940
> Project: Log4j 2
> Issue Type: Bug
> Components: API
> Affects Versions: 2.13.3
> Reporter: Peter H
> Assignee: Ralph Goers
> Priority: Major
>
> We're encountering an issue similar to [LOG4J2-2792] and [LOG4J2-2880] but it
> isn't because of the use of Location, but because of the use of dynamically
> created loggers that we then refer to via
> {{org.slf4j.LoggerFactory.getLogger(method.getDeclaringClass())}}. This
> attempts to get the caller class and ends up walking the stack as in the
> stack trace example below. This is known to be rather problematic (from the
> performance perspective) and even becomes worse with the time (until the JVM
> restart, or full GC) - https://bugs.openjdk.java.net/browse/JDK-8222942 for
> example.
> However instead of doing it this rather expensive way, it may be possible to
> use an improved approach similar to what jboss-logging library developers
> used when working on the following issues:
> https://bugzilla.redhat.com/show_bug.cgi?id=1813436
> https://issues.redhat.com/browse/LOGMGR-263
> The related commit:
> https://github.com/jboss-logging/jboss-logmanager/commit/fc1fc3b509df9797ff06a423878a5b113f6281f8
> Can you check whether something useful may be brought in from that?
> {noformat}at
> java.lang.StackStreamFactory$AbstractStackWalker.fetchStackFrames(java.base@11.0.8/Native
> Method)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.fetchStackFrames(java.base@11.0.8/StackStreamFactory.java:386)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.getNextBatch(java.base@11.0.8/StackStreamFactory.java:322)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.peekFrame(java.base@11.0.8/StackStreamFactory.java:263)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.hasNext(java.base@11.0.8/StackStreamFactory.java:351)
> at
> java.lang.StackStreamFactory$StackFrameTraverser.tryAdvance(java.base@11.0.8/StackStreamFactory.java:593)
> at
> java.util.stream.ReferencePipeline.forEachWithCancel(java.base@11.0.8/ReferencePipeline.java:127)
> at
> java.util.stream.AbstractPipeline.copyIntoWithCancel(java.base@11.0.8/AbstractPipeline.java:502)
> at
> java.util.stream.AbstractPipeline.copyInto(java.base@11.0.8/AbstractPipeline.java:488)
> at
> java.util.stream.AbstractPipeline.wrapAndCopyInto(java.base@11.0.8/AbstractPipeline.java:474)
> at
> java.util.stream.FindOps$FindOp.evaluateSequential(java.base@11.0.8/FindOps.java:150)
> at
> java.util.stream.AbstractPipeline.evaluate(java.base@11.0.8/AbstractPipeline.java:234)
> at
> java.util.stream.ReferencePipeline.findFirst(java.base@11.0.8/ReferencePipeline.java:543)
> at
> org.apache.logging.log4j.util.StackLocator.lambda$getCallerClass$6(StackLocator.java:58)
> at
> org.apache.logging.log4j.util.StackLocator$$Lambda$1226/0x00000008414fec40.apply(Unknown
> Source)
> at
> java.lang.StackStreamFactory$StackFrameTraverser.consumeFrames(java.base@11.0.8/StackStreamFactory.java:534)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.doStackWalk(java.base@11.0.8/StackStreamFactory.java:306)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.callStackWalk(java.base@11.0.8/Native
> Method)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.beginStackWalk(java.base@11.0.8/StackStreamFactory.java:370)
> at
> java.lang.StackStreamFactory$AbstractStackWalker.walk(java.base@11.0.8/StackStreamFactory.java:243)
> at java.lang.StackWalker.walk(java.base@11.0.8/StackWalker.java:498)
> at
> org.apache.logging.log4j.util.StackLocator.getCallerClass(StackLocator.java:57)
> at
> org.apache.logging.log4j.util.StackLocatorUtil.getCallerClass(StackLocatorUtil.java:67)
> at
> org.apache.logging.slf4j.Log4jLoggerFactory.getContext(Log4jLoggerFactory.java:45)
> at
> org.apache.logging.log4j.spi.AbstractLoggerAdapter.getLogger(AbstractLoggerAdapter.java:48)
> at
> org.apache.logging.slf4j.Log4jLoggerFactory.getLogger(Log4jLoggerFactory.java:30)
> at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:363)
> at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:388)
> at LoggerAspect.isLogLevelEnabled(LoggerAspect.java:91)
> ...{noformat}
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