Before WildFly 28 only supported the ability to encode session affinity information into the JSESSIONID cookie, which is already used to uniquely identify a session. This plays nicely with the httpd family of load balancer modules (e.g. `mod_cluster`, `mod_proxy_balancer`, `mod_jk`) for which this mechanism was designed.

However, many load balancers rely on a separate cookie for implementing sticky sessions (e.g. HAProxy, IIS, Nginx, etc.),
and thus lack the ability to allow WildFly to guide requests for a given session to the server that can most efficiently handle it.

To resolve this, a configuration attribute has been added within the Undertow subsystem to allow the use of a configurable cookie to store session affinity information.

The mod_cluster project should be expanded to support this affinity cookie.