After migration from EAP 7.2.7 to 7.3(or 7.3.1), tags related to clustering [1] are lost.

Because of this, we get the warn log message.

 1.The following 3 tags are missing.

(a). <extension module="org.wildfly.extension.clustering.web"/>

(b). <subsystem xmlns="urn:jboss:domain:distributable-web:2.0" default-session-management="default" default-single-sign-on-management="default">

       <infinispan-session-management name="default" cache-container="web" granularity="SESSION">

           <primary-owner-affinity/>

       </infinispan-session-management>

       <infinispan-single-sign-on-management name="default" cache-container="web" cache="sso"/>

       <infinispan-routing cache-container="web" cache="routing"/>

   </subsystem>

(c). In <cache-container name="web" default-cache="passivation" module="org.wildfly.clustering.web.infinispan"> tag,

     <local-cache name="sso">

         <locking isolation="REPEATABLE_READ"/>

         <transaction mode="BATCH"/>

     </local-cache>

     <local-cache name="routing"/>

 2. WARN log message

Because of this, we get the following warn log message. Could you please explain what this warn log means?

~~~

2020-06-25 09:54:54,173 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

~~~

Attached files are standalone.xml files which can be got when migrating from 7.2.7 to 7.3.1.

[1] 3.9. Clustering

#https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.3/html/7.3.0_release_notes/new_features_and_enhancements#clustering