cp -a standalone node-1
cp -a standalone node-2
./bin/standalone.sh -c standalone-ha.xml -Djboss.server.base.dir=`pwd`/node-1 -Djboss.node.name=host1
./bin/standalone.sh -c standalone-ha.xml -Djboss.server.base.dir=`pwd`/node-2 -Djboss.node.name=host2 -Djboss.socket.binding.port-offset=100

#cluster was formed
#08:20:57,753 INFO [org.infinispan.CLUSTER] (MSC service thread 1-8) ISPN000094: Received new cluster view for channel ejb: [host1|1] (2) [host1, host2]

# Generate the load. It will acces port 8080, thus node-1
./jmeter.sh -n -t /path/to/reproducer/jmeter-testcase.jmx

# Kill the node-1 by Ctrl + C in node-1 terminal.
# You don't need to wait for previous step to be finished.

08:21:48,681 TRACE [org.wildfly.clustering.web.infinispan] (InfinispanSessionManager - 1) Session tYYEQST88BzExZLsCGdmBe9qdmwtPKRA6G86AziT will expire in 59719 ms

08:22:48,400 TRACE [org.wildfly.clustering.web.infinispan] (SessionExpirationScheduler - 1) Expiring session tYYEQST88BzExZLsCGdmBe9qdmwtPKRA6G86AziT
 08:22:48,402 TRACE [org.wildfly.clustering.web.infinispan] (SessionExpirationScheduler - 1) Session tYYEQST88BzExZLsCGdmBe9qdmwtPKRA6G86AziT has expired.
 08:22:48,403 TRACE [org.wildfly.clustering.web.infinispan] (SessionExpirationScheduler - 1) Session tYYEQST88BzExZLsCGdmBe9qdmwtPKRA6G86AziT will be removed

Mon Jun 7 08:46:34 AM CEST 2021
PID: 27682
# before GC --------------------------
 num #instances #bytes class name (module)
 16: 16000 384000 org.wildfly.clustering.web.infinispan.session.fine.SessionAttributeKey
 781: 32 512 org.wildfly.clustering.web.infinispan.session.SessionAccessMetaDataKey
 782: 32 512 org.wildfly.clustering.web.infinispan.session.SessionCreationMetaDataKey
 783: 32 512 org.wildfly.clustering.web.infinispan.session.fine.SessionAttributeNamesKey
--------------------------------------
# trigger GC to clean up for testing purpose 
27682:
Command executed successfully
# after GC ---------------------------
 num #instances #bytes class name (module)
 16: 16000 384000 org.wildfly.clustering.web.infinispan.session.fine.SessionAttributeKey
 754: 32 512 org.wildfly.clustering.web.infinispan.session.SessionAccessMetaDataKey
 755: 32 512 org.wildfly.clustering.web.infinispan.session.SessionCreationMetaDataKey
 756: 32 512 org.wildfly.clustering.web.infinispan.session.fine.SessionAttributeNamesKey
--------------------------------------

http localhost:10090/metrics | grep jboss_undertow_active_sessions
# HELP jboss_undertow_active_sessions Number of active sessions
# TYPE jboss_undertow_active_sessions gauge
jboss_undertow_active_sessions\{deployment="hello.war",subdeployment="hello.war",microprofile_scope="vendor"} 32.0