Major Description
Reported here: https://github.com/apache/logging-log4j2/pull/251
Stack Trace TLABs Total TLAB Size(bytes) Pressure(%) java.lang.ThreadLocal$ThreadLocalMap.set(ThreadLocal, Object) line: 481 10 3,638,864 56.192 java.lang.ThreadLocal$ThreadLocalMap.access$100(ThreadLocal$ThreadLocalMap, ThreadLocal, Object) line: 298 10 3,638,864 56.192 java.lang.ThreadLocal.setInitialValue() line: 184 10 3,638,864 56.192 java.lang.ThreadLocal.get() line: 170 10 3,638,864 56.192 org.apache.logging.log4j.core.async.AsyncLoggerConfig.log(LogEvent, LoggerConfig$LoggerConfigPredicate) line: 91 10 3,638,864 56.192
We clear and re-set a threadlocal value, which plays with the internal thread-map size like an accordion, increasing probability unused thread entries will be removed. By setting back to a default value rather than clearing the threadlocal we can avoid allocation.