Suppose I have one web application ABC , ABC has one link for module Name XYZ which is deployed in other JBOss or Wildfly server. When user login into application ABC , and click on link XYZ I have to use same authentication of ABC to XYZ. What is the proper way to do it ?
The Web (Undertow) Reference Guide for Wildfly (which was last updated July, 2014) states this:
Sharing sessions between wars in an ear
Undertow allows you to share sessions between wars in an ear, if it is explicitly configured to do so. Note that if you use this feature your applications may not be portable, as this is not a standard servlet feature.
In order to enable this you must include a shared-session-config element in the jboss-all.xml file in the META-INF directory of the ear:
<jboss umlns="urn:jboss:1.0">
<shared-session-config xmlns="urn:jboss:shared-session-config:1.0">
<session-config>
<cookie-config>
<path>/</path>
</cookie-config>
</session-config>
</shared-session-config>
</jboss>
This element is used to configure the shared session manager that will be used by all wars in the ear. For full details of all the options provided by this file please see the schema at https://github.com/wildfly/wildfly/blob/master/undertow/src/main/resources/schema/shared-session-config_1_0.xsd, however in general it mimics the options that are available in jboss-web.xml for configuring the session.
This was added in WFLY-1891 (Fix Versions: 8.2.0.Final, 9.0.0.Alpha1), the comments on which note that it doesn't work in a cluster (as of April, 2014).
See also another SO post - Session sharing on WildFly is not working
Edit:
WFLY-3270 - Clustered support for HTTPSession sharing between wars delivered in an EAR notes that clustering was resolved in 9.0.0.Alpha1.