The only configuration step to enable (or disable) the “Keep Session Alive” functionality is found in the portal Security and Access Options page and involves clicking (or unclicking) the “Keep Session Alive” check box which this option is only available utilizing portal style 4 customer portals.
The feature makes sure that the portal session does not expire and will override the IIS timeout option that may have been entered into the webconfig & IIS settings on the server. This feature was developed originally in 9.0.1 hotfix 2 and perfected in Hotfix 3.
Caveats:
1. This will affect the visitors report. The visitors report relies on unique sessions and when the “keep alive” functionality is enabled, it is possible to see reduced visits logged due to retaining the same session ID for all the articles have been selected to search upon.
The Visitors Report is generated from a series of scheduled tasks fired in a set order and draws its data based off of unique customer session IDs used in the portals. A simplified overview is that when a user first accesses the portal they are given a session ID value and a visit is logged in the visitor reports table. However, actions taken there after by the customer are not counted as separate visits to the portal or any of the KB articles searched upon and selected as long as the session ID remains the same with their current browser they are utilizing.
If the portal in question has the "Keep Session Alive" option enabled, then the users' session IDs will remain the same for as long as the portal is open in a browser on their machine. It is possible in those cases to have a single visit counted for multiple days of use because a new session ID is not generated until the user logs out and logs back in again. Since the purpose of the "Keep Session Alive" functionality is to reduce or eliminate the need for users to have to keep logging back in, it is expected that logged unique visits will decrease with it in use. If using that feature on the portal(s), then that could explain the drop in logged visits.
2. Enabling the “Keep Session Alive” feature carries with it the same potential for resource drain as extending session time out values: For more information on that, please see this related article 3457 or 3456 on extending portal timeout values..
Please see article 4086 for known issues.