AlexProgrammerDE opened a new issue, #3234: URL: https://github.com/apache/logging-log4j2/issues/3234
## Description Presumable due to https://github.com/apache/logging-log4j2/commit/a1dfa853c96604ded1f253da2ec25f8f2f95ef25 my application throws an error when loggers get changed from multiple threads. This is likely because `InternalLoggerRegistry#getLoggers` does not return a thread-safe stream. Streams are by nature evaluated on the fly, thus still using the values after `readLock` was unlocked. When multiple threads modify `loggerRefByNameByMessageFactory`, sometimes it errors with the attached error. This happens inconsistently because it's a race condition, but I've been able to get this error a few times. ## Configuration **Version:** 2.24.2 **Operating system:** Windows **JDK:** openjdk version "21.0.4" 2024-07-16 LTS ## Logs ``` java.util.ConcurrentModificationException: null at java.base/java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1792) ~[?:?] at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762) ~[?:?] at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[?:?] at java.base/java.util.WeakHashMap$ValueSpliterator.forEachRemaining(WeakHashMap.java:1223) ~[?:?] at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?] at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[?:?] at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151) ~[?:?] at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174) ~[?:?] at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?] at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[?:?] at org.apache.logging.log4j.core.LoggerContext.updateLoggers(LoggerContext.java:776) ~[?:?] at org.apache.logging.log4j.core.LoggerContext.updateLoggers(LoggerContext.java:766) ~[?:?] at org.apache.logging.log4j.core.config.Configurator.setLevel(Configurator.java:379) ~[?:?] at org.apache.logging.log4j.core.config.Configurator.setLevel(Configurator.java:414) ~[?:?] at com.soulfiremc.server.SoulFireServer.setupLogging(SoulFireServer.java:213) ~[?:?] at com.soulfiremc.server.SoulFireServer.setupLoggingAndVia(SoulFireServer.java:208) ~[?:?] at com.soulfiremc.server.InstanceManager.start(InstanceManager.java:194) ~[?:?] at com.soulfiremc.server.SoulFireScheduler.lambda$wrapFuture$6(SoulFireScheduler.java:140) ~[?:?] at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804) ~[?:?] at com.soulfiremc.server.SoulFireScheduler.runCommand(SoulFireScheduler.java:154) ~[?:?] at com.soulfiremc.server.SoulFireScheduler.lambda$schedule$2(SoulFireScheduler.java:79) ~[?:?] at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423) ~[?:?] at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) ~[?:?] at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) ~[?:?] at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) ~[?:?] at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) ~[?:?] at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) ~[?:?] ``` This shows the stream being collected due to the forEach call in LoggerContext, but there being no read lock, therefore causing this race condition. ## Reproduction I unfortunately cannot provide an example because I do not have much experience with reproducing race conditions. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: notifications-unsubscr...@logging.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
