Application Server: Session Sharing

Session Sharing Between Domains

Sessions are tied to the JSESSIONID cookie.

By default, the JSESSIONID cookie uses the full host name for the cookie domain. So requests to www.foo.com will not share cookies (and thus sessions) with secure.foo.com.

cookie-domain

If all your host names end with "foo.com", then simply set "domain-cookie" to share cookies between hosts:

<session-config>
  <cookie-domain>foo.com</cookie-domain>
  ...
</session-config>

cookie-domain-regexp

If you have more than one domain using the same web application, you can use the cookie-domain-regexp parameter.

cookie-domain-regexp accepts a regular expression used to extract the domain from the requested host. Probable configuration:

<session-config>
   <cookie-domain-regexp>[^.]*\.[^.]*$</cookie-domain-regexp>
   ...
 </session-config>

For example, using this regexp will produce the following:

Host: xxx.yyy.zzz.foo.com =  Set-Cookie domain: foo.com
Host: zzz.foo.com =  Set-Cookie domain: foo.com
Host: foo.com =  Set-Cookie domain: foo.com
Host: bar.com =  Set-Cookie domain: bar.com

This configuration belongs in the app-tier.