Limit Concurrent Users Per Project

[den1s]

Hello,

Having read the forum regarding concurrent users, I am now very interested to know how i can limit the number of users per project. I have 3 apps on my Web Server, but dont want to affect them all. I need to keep them all unique.

So my ultimate question is, what would i need to to limit the number of logins/sessions in one of my apps?

Thanks,

Denis

[Steve Wood]

Re: Limit Concurrent Users Per Project

I forget the function that returns the number of current connections. It counts the current sessions. You take that number, minus one, and its supposed to be your current sessions (I find the function consumes one session).

So perhaps in a Header page that tops all pages, you save the current session count in to a session variable. On the Login.A5W page, in Source, just below where it runs the Login component, put xbasic code that says if the current session count is above X, prohibit login.

That code would look something like this:

if eval_valid("session.currentsessions")
if session.currentsessions > "5"
response.redirect("sorrytomanyusers.a5w")
end if
end if

That would redirect the user to a page prior to allowing login if count was over 5, but allow them to pass to the login dialog if less than 5.

To ensure your current sessions is roughly equal to your ACTUAL current users, you'd want to use the Security option to close the session after a period of inactivity.

I did not test any of this, but the logic will work.

[Phil Rolf]

Re: Limit Concurrent Users Per Project

To count sessions you use a5_count_websessions() Here is a bit of xbasic on my a5w page that counts the session and displays it on my a5w page (for quick reference) and stores some info about the sessions in a log file.

<%a5
dim nSessions as N
nSessions = a5_count_websessions()
dim counter_file as c
counter_file = "<ADB_Path>\websesscntr.txt"
countsess = "Number Of Sessions "+str(nSessions,4,0)+"  <"+date()+">  <"+time()+">   "+crlf()
save_to_file(countsess,counter_file,.t.)
%>
<font 
face=Arial size =1 >
<%a5
?str(nSessions,3,0)
%>

[Steve Wood]

Re: Limit Concurrent Users Per Project

I was playing around with this because I thought it would be nice to display the "online now" value. I lead you astray, the count of sessions does NOT mean the number of users logged in. It is just a count of the number of browsers open to your website, not necessarily logged in.

So I don't know how to capture the number of currently logged on users other than to count them as they log in, and count them when they log off. But I don't know how to do the latter part of that equation unless they actually click a Logout button, which nobody does.

I think we need to ask Alpha if there is some way to interrogate the Security Framework to see who is logged in. Or some way of knowing that a login has expired so you can deduct the value.

[Phil Rolf]

Re: Limit Concurrent Users Per Project

You are correct on the number of sessions. What I do is look at the number on my home page to see what kind of activity there is. I look at the number with a grain of salt....

Counting the number of logins is the simple part. But deducting is cannot be done as we do not know if the login session has expired and you cannot rely on users to logoff. It would be nice to have a A5 variable that you can increment as a user logs in. Then A5 would deduct from this variable if the login session has expired.

I have not spent the time to learn the Security Framework so I cannot comment on that area.

[den1s]

Re: Limit Concurrent Users Per Project

I came across your answers to my question and forgot to thank you both.

'Thank you'

Denis

[webmaster]

Re: Limit Concurrent Users Per Project

This is an intersting problem, and difficult to solve for the reasons that have been mentioned. An additional problem with counting sessions in this case is also that the count is for the whole server, not individual applications.

I would use a server variable, or rather 3 of them, to count the users in each application. Upon login, you count incrment the number. But you would also need logic that was aware of the session timeout value to also decrement the count as user logins expire. This will also be a less than perfect count.

[den1s]

Re: Limit Concurrent Users Per Project

Thanks for the info Joe. I have used Phil's script for my app. However, i would be useful if Alpha could provide a facility to count users logged in instead of sessions opened.

Denis