JBoss - Java heap retention in session cache DefaultDataContainer after session listener exceptions

Issue

• We see exceptions during session destruction from a session listener and after enough such exceptions an OutOfMemoryError is eventually reached with heap consumed by many org.infinispan.container.entries.ImmortalCacheEntrys in a org.infinispan.container.impl.DefaultDataContainer session cache

WARN  [org.wildfly.clustering.web.infinispan] (SessionExpirationScheduler - 1) WFLYCLWEBINF0004: Failed to expire session ypieHzHp1gCnVEibsm_ZiYShDaLggbRmYBpa65re: java.lang.RuntimeException: java.lang.NullPointerException
    at io.undertow.servlet//io.undertow.servlet.core.SessionListenerBridge.sessionDestroyed(SessionListenerBridge.java:75)
    at io.undertow.core@2.0.30.SP2-redhat-00001//io.undertow.server.session.SessionListeners.sessionDestroyed(SessionListeners.java:61)
    at org.wildfly.clustering.web.undertow@7.2.8.GA-redhat-00002//org.wildfly.clustering.web.undertow.session.UndertowSessionExpirationListener.sessionExpired(UndertowSessionExpirationListener.java:56)
    at org.wildfly.clustering.web.infinispan@7.2.8.GA-redhat-00002//org.wildfly.clustering.web.infinispan.session.ExpiredSessionRemover.remove(ExpiredSessionRemover.java:61)
    at org.wildfly.clustering.web.infinispan@7.2.8.GA-redhat-00002//org.wildfly.clustering.web.infinispan.session.ExpiredSessionRemover.remove(ExpiredSessionRemover.java:40)
    at org.wildfly.clustering.web.infinispan@7.2.8.GA-redhat-00002//org.wildfly.clustering.web.infinispan.session.SessionExpirationScheduler$ExpirationTask.run(SessionExpirationScheduler.java:149)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)
    at org.jboss.threads@2.3.3.Final-redhat-00001//org.jboss.threads.JBossThread.run(JBossThread.java:485)
Caused by: java.lang.NullPointerException
    at deployment.02721921.war//com.listeners.CustomHttpSessionListener.sessionDestroyed(CustomHttpSessionListener.java:28)
    at io.undertow.servlet//io.undertow.servlet.core.ApplicationListeners.sessionDestroyed(ApplicationListeners.java:328)
    at io.undertow.servlet//io.undertow.servlet.core.SessionListenerBridge.doDestroy(SessionListenerBridge.java:98)
    at io.undertow.servlet//io.undertow.servlet.core.SessionListenerBridge.access$000(SessionListenerBridge.java:41)
    at io.undertow.servlet//io.undertow.servlet.core.SessionListenerBridge$1.call(SessionListenerBridge.java:54)
    at io.undertow.servlet//io.undertow.servlet.core.SessionListenerBridge$1.call(SessionListenerBridge.java:51)
    at io.undertow.servlet//io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:42)
    at io.undertow.servlet//io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
    at org.wildfly.extension.undertow@7.2.8.GA-redhat-00002//org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)
    at org.wildfly.extension.undertow@7.2.8.GA-redhat-00002//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
    at org.wildfly.extension.undertow@7.2.8.GA-redhat-00002//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
    at org.wildfly.extension.undertow@7.2.8.GA-redhat-00002//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
    at org.wildfly.extension.undertow@7.2.8.GA-redhat-00002//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1504)
    at io.undertow.servlet//io.undertow.servlet.core.SessionListenerBridge.sessionDestroyed(SessionListenerBridge.java:73)
    ... 12 more