Share session data between 2 subdomains

Question

I am using tomcat 7.0.6 with jdk 1.6.0_22

Is it possible to share session data between 2 different domains with a common subdomain such as a.mydomain.com and b.mydom

Answer 1

Set the sessionCookieDomain attribute of element of the webapp in question to .mydomain.com (note the leading dot, this is very important). This will allow the webbrowser to share cookies among all subdomains.

If you actually have multiple webapp contexts and you want to share the session between them as well, then you also need to set sessionCookiePath attribute of element of the webapps in question to /.

In a nutshell:

See also:

• Tomcat 7 configuration reference - The Context container

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For Tomcat 6 users: note that this was introduced in Tomcat 6.0.27. For those who can't upgrade, you would need a Valve to modify the cookie domain, eventually in combination with emptySessionPath attribute in element in /conf/server.xml for the case that you've multiple webapp contexts for which you'd like to share the session.