# How to get all the user\_id from Session **URL:** \ **Category:** Rails\ **Created:** [March 31, 2008, 2:17pm UTC](https://www.ruby-forum.com/t/how-to-get-all-the-user-id-from-session/133423 "2008-03-31T14:17:51Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![adistarmid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f14d63/32.png) [@adistarmid](https://www.ruby-forum.com/u/adistarmid)\ **Post date:** [March 31, 2008, 2:17pm UTC](https://www.ruby-forum.com/t/how-to-get-all-the-user-id-from-session/133423/1 "2008-03-31T14:17:51Z")
Using session can record users’ id when users log in, like session[:user\_id]. If I want to know how many users are online, so how can I get all the users’s id from session? Thanks! ---
**Author:** ![adistarmid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f14d63/32.png) [@adistarmid](https://www.ruby-forum.com/u/adistarmid)\ **Post date:** [March 31, 2008, 2:35pm UTC](https://www.ruby-forum.com/t/how-to-get-all-the-user-id-from-session/133423/2 "2008-03-31T14:35:39Z")
On 31 Mar 2008, at 13:17, Bob Song wrote: > Using session can record users’ id when users log in, like > session[:user\_id]. > > If I want to know how many users are online, so how can I get all the > users’s id from session? Depending on what session store you are using this ranges from fiddly to impossible. With the cookie store for example (the default since rails 2) the session is stored client side, so this is impossible. With other ones you’d have to load each session (while somehoe working out which ones are just dead/expired). Fred ---
**Author:** ![adistarmid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f14d63/32.png) [@adistarmid](https://www.ruby-forum.com/u/adistarmid)\ **Post date:** [March 31, 2008, 4:14pm UTC](https://www.ruby-forum.com/t/how-to-get-all-the-user-id-from-session/133423/3 "2008-03-31T16:14:35Z")
On 31 Mar 2008, at 14:34, Frederick C. wrote: > out which ones are just dead/expired). > Indeed, a user count using sessions is always a guess. The only way to > have a reliable user online count, is by using a push server like > juggernaut for example. And that’s going to get you into trouble if > you want to deploy on a shared hosting account (since you have to run > a separate push server). Best regards Peter De Berdt ---
**Author:** ![adistarmid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/f14d63/32.png) [@adistarmid](https://www.ruby-forum.com/u/adistarmid)\ **Post date:** [March 31, 2008, 5:28pm UTC](https://www.ruby-forum.com/t/how-to-get-all-the-user-id-from-session/133423/4 "2008-03-31T17:28:45Z")
What they said. 🙂 The “how many users are online” question is too relative anyway. Visiting a web page is a single, transactional action (most of the time) so you have: at XYZ user ABC requested page 123 and it was returned. So is that user “online”? What about 5 minutes after XYZ? are they still “online”? what about 5 hours or 5 days? Do you see the conundrum here? On the other hand, if you set a threshold for yourself, like: “online” means last activity within the past 1 hour, and then set a “last\_activity\_at” datetime field on the user table, and then have an after\_filter that updates that field for each user action. Now, you have a way to query by showing all users where last\_activity\_at is within 1 hour ago. It’s still fuzzy because “online” is a bad way to think about visitors to a web app. But for some apps, like campfire for example, the domain of the app makes it a reasonable question. I.e. if your last comment was within X minutes and you haven’t explicitly logged out, then you are still “online”. But after Y minutes you are “idle” and after Z minutes you are “offline”. You have to define waht those mean for your app, though. Just some thoughts. -Danimal