In our iOS app, users login and logout frequently. On login we call
identify() and on logout we call
reset(). In the logged out state, users can perform some actions that are tracked by Mixpanel using anonymous user id. When they later login, the
identify() call merges this anonymous user id with their real user id. So far so good.
But after each logout and
reset(), a new random anonymous user id is set by Mixpanel library. So for each logout-login cycle, Mixpanel adds yet another anonymous user id to the set the user ids that identify a particular user. The API docs say that this set is limited to 500 distinct ids.
So what do we do about users that login-logout more than 500 times? It’s not hard to exceed this limit for long term loyal users.