Determine how many users are visiting a site -now 1

[dkdude]

A client of mine would like to be able to see the number of users visiting her site - real time.

I know that I can examine the server access log to pull the information, but the provider won't give me access to it.

Is that information available through any Apache server vars? Do I need to use sessions?


Any thoughts?

 

[thedaver]

You can count the sessions still alive. It's not perfect, but it's reasonable.

'ls -1 /tmp/sess* | wc -l'

Or if you're using sessions from SQL, it's a simple call away...

Now, if you're NOT using sessions, then you'd need to build something into the cookies to post a value that has, say, a 5 minute time-to-live that your server keeps. If that cookie doesn't come by to refresh the "timer" then you decrement your live user count.

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[dkdude]

Thanks thedaver

Neat and simple solution, just to count the session files. I will try to see if her provider will let me access the session dir. I know I can use your idea elsewhere, so have a star

Just to be sure I got sessions right - the won't work if the client have turned off cookies, right?

 

[thedaver]

PHP sessions are adaptive (unless you over-ride).
Sessions are either carried through cookies or as a getstring item on the URL.

Irrespective of the client side, your server should only maintain them in one place, unless your code is over-riding the Apache (or web server)'s default with PHP specific isntructions to write to a RDBMS or RAM.

(Your star didn't stick, BTW, but thanks!)

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[dkdude]

... sorry about the star. This time I did actually click on the link ;-)

I will give it a go - it's a nice and speedy solution and works fine on my development server. Sweet!

 

[thedaver]

file match pattern might be "SESS*", FYI.

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[jpadie]

the "now'ness" of the session directory will depend on you garbage collection and session lifetime parameters in your php.ini file.

i mostly prefer to have sessions last quite a while (at least a day or so) as I tend to use them both for logging and for user navigation/preference management (I time out login connections separately).

so for active users I tend to use an alternative which is to create a small table with fields sessionID and lastseen. sessionID must be a primary key

then in each page run the following

session_start();
define ("SESSIONTABLE", ""); //session table
$now = time();
$active = 10; //definition of active in minutes
//connect to db

flush_nonActive()
touchSession();
$num_active_users = getActiveUsers();

//these could be held in a library file
function flush_nonActive(){
  //deletes records that have not been 'touched' in last x minutes
  mysql_query("delete from ".SESSIONTABLE." where lastseen < " $now-$active);
}

function touchSession() {
 //touches a session to record last activity time
 mysql_query("replace into ".SESSIONTABLE." set sessionID = '".session_id()."', lastseen=$now");
}
function getActiveUsers() {
 //simple record count
 return mysql_result(mysql_query("select count(*) from ".SESSIONTABLE), 0, 0);
}