WFLYCLWEBUT0007: Warning: clustering.web extension and distributable-web subsystem are not present after migrating from EAP 7.2 to 7.3+ by migration tool

Issue

Getting WFLYCLWEBUT0007 WARN message while starting up, after migrating from EAP 7.2 to 7.3+ by jboss-server-migration.sh/bat.

WARN  [org.wildfly.clustering.web.undertow] (ServerService Thread Pool -- 71) WFLYCLWEBUT0007: No routing provider found for default-server; using legacy provider based on static configuration

Also, getting the following WFLYCLWEBUT0005 WARN message when deploying a web application that has <distributable/> in web.xml.

WARN  [org.wildfly.clustering.web.undertow] (MSC service thread 1-4) WFLYCLWEBUT0005: No distributable session management provider found for example.war; using legacy provider based on <replication-config/>