Measuring session length will depend on your app. For a typical web app, what you would do is have some sort of process that updates the current session timesta

Measuring session length will depend on your app. For a typical web app, what you would do is have some sort of process that updates the current session timestamp when a new user action happens. Then, another process will go through currently active sessions and automatically close those that have been inactive for longer than a certain time period. The actual time period depends on your app, of course. I haven't spotted a programmer's guide to measuring these metrics. There are a number of people on this site who would be very qualified to write one, though (patio11 comes to mind).