Hello, we use logback instead of log4j and get this error after upgrading Flink to 1.20. It seems that 1.20 does not support logback 1.2.13. We cannot upgrade because, as documentation states, "Logback 1.3+ requires SLF4J 2, which is currently not supported". We see that the 1.20 implementation of PekkoRpcActor.handleControlMessage has changed and now call MdcUtils that seems not compatible with logback 1.2.x. Do you think this problem will be solved in the next versions?
Suppressed: java.lang.NullPointerException: Cannot invoke "java.util.Map.size()" because "m" is null Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Map.size()" because "m" is null at java.base/java.util.HashMap.putMapEntries(HashMap.java:495) at java.base/java.util.HashMap.putAll(HashMap.java:783) at java.base/java.util.Collections$SynchronizedMap.putAll(Collections.java:2682) at ch.qos.logback.classic.util.LogbackMDCAdapter.setContextMap(LogbackMDCAdapter.java:197) at org.slf4j.MDC.setContextMap(MDC.java:264) at org.apache.flink.util.MdcUtils.lambda$withContext$0(MdcUtils.java:48) at org.apache.flink.runtime.rpc.pekko.PekkoRpcActor.handleControlMessage(PekkoRpcActor.java:208) at org.apache.pekko.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:33) at org.apache.pekko.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:29) at scala.PartialFunction.applyOrElse(PartialFunction.scala:127) at scala.PartialFunction.applyOrElse$(PartialFunction.scala:126) at org.apache.pekko.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:29) at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:175) at scala.PartialFunction$OrElse.applyOrElse(PartialFunction.scala:176) at org.apache.pekko.actor.Actor.aroundReceive(Actor.scala:547) at org.apache.pekko.actor.Actor.aroundReceive$(Actor.scala:545) at org.apache.pekko.actor.AbstractActor.aroundReceive(AbstractActor.scala:229) at org.apache.pekko.actor.ActorCell.receiveMessage(ActorCell.scala:590) at org.apache.pekko.actor.ActorCell.invoke(ActorCell.scala:557) at org.apache.pekko.dispatch.Mailbox.processMailbox(Mailbox.scala:280) at org.apache.pekko.dispatch.Mailbox.run(Mailbox.scala:241) at org.apache.pekko.dispatch.Mailbox.exec(Mailbox.scala:253) at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373) at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182) at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655) at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622) at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165) Eliana Clementi
