Hi,

You can check this link for configuring the session time out , https://www.odoo.com/forum/help-1/question/why-there-is-not-timeout-period-session-connection-to-expire-in-openerp-8203

Also you can check the session_gc function defined in the http.py file, this will give you the idea about the how the inactive session are removed. Normally if the session is inactive for a week it will get expired.

Thanks

You can get an idea from https://github.com/OCA/server-tools/tree/8.0/inactive_session_timeout