property

zero or more 

Specifies a property or a variable. 

session-file-name

none; state is not preserved across restarts 

(optional) Specifies the absolute or relative path to the directory in which the session state is preserved between application restarts, if preserving the state is possible. A relative path is relative to the temporary directory for this web application.  

reap-interval-in-seconds

60

(optional) Specifies the time between checks for expired sessions. 

Set this value lower than the frequency at which session data changes. For example, this value should be as low as possible (1 second) for a hit counter servlet on a frequently accessed web site, or you could lose the last few hits each time you restart the server.

max-sessions

-1

(optional) Specifies the maximum number of sessions that can be in cache, or -1 for no limit. After this, an attempt to create a new session causes an IllegalStateException to be thrown.

session-id-generator-classname

internal class generator 

(optional) Not implemented. Do not use.