Count of current visitors

**John** · Jul 19 '05, 01:29 PM

Re: Count of current visitors

Did you refresh your 1° page after closing 2 and 3 ?

**Bob Barrows [MVP]** · Jul 19 '05, 01:29 PM

Re: Count of current visitors

cc@cc.com wrote:[color=blue]
> From the popular website At this link:
> http://www.w3schools.com/asp/asp_globalasa.asp
>
> I got this code, but it does not work on my server... I can open three
> IE browsers and watch the count go to three. Upon closing two, each
> having separate sessions (and session ID's of course), the count
> remains at three! I'm not looking for alternative ways of doing this:
> I'm interested in knowing why the application variable does not get
> reduced upon ending the session by closing the browser. Any ideas?
>[/color]
This seems to be a very prevalent misconception.

The session does not end when the user closes his browser. Think about it.
How can the server know when a user closes his browser? Answer: it can't.
HTTP is a stateless protocol. There is no "signal" sent to the server when a
user closes his browser, or navigates to another website. The only way a web
server has of knowing a session is still in use is if it receives requests
for pages with the session ID in the request headers.

There are only two ways a session will end:

1. A Session.Abandon statement is executed
2. The session's timeout period is exceeded, i.e., the server receives no
new requests for pages containing that session id for a longer period of
time than the session's timeout setting.

So, in the scenario you describe above: if your session timeout setting is
at the default value of 20 min., the user count will get adjusted 20 min.
after the user closes his browser.

Aaron describes a way to get a more accurate count of current users using a
database in this article:

500 Internal Server Error

http://www.aspfaq.com/show.asp?id=2491

HTH,
Bob Barrows
--
Microsoft MVP - ASP/ASP.NET
Please reply to the newsgroup. This email account is my spam trap so I
don't check it very often. If you must reply off-line, then remove the
"NO SPAM"

**Samuel Hon** · Jul 19 '05, 01:29 PM

Re: Count of current visitors

Sessions timeout after n minutes (default is 20 I think) so you'll
have to be patient (or change the setting)

cc@cc.com wrote in message news:<410dd003. 84332156@news.d allas.sbcglobal .net>...[color=blue]
> From the popular website At this link:
> http://www.w3schools.com/asp/asp_globalasa.asp
>
> I got this code, but it does not work on my server... I can open three
> IE browsers and watch the count go to three. Upon closing two, each
> having separate sessions (and session ID's of course), the count
> remains at three! I'm not looking for alternative ways of doing this:
> I'm interested in knowing why the application variable does not get
> reduced upon ending the session by closing the browser. Any ideas?
>
> Thanks,
> See below:
>
> The Global.asa file:
>
> <script language="vbscr ipt" runat="server">
> Sub Application_OnS tart
> Application("vi sitors")=0
> End Sub
>
> Sub Session_OnStart
> Application.Loc k
> Application("vi sitors")=Applic ation("visitors ")+1
> Application.UnL ock
> End Sub
>
> Sub Session_OnEnd
> Application.Loc k
> Application("vi sitors")=Applic ation("visitors ")-1
> Application.UnL ock
> End Sub
> </script>
>
> To display the number of current visitors in an ASP file:
>
> <html>
> <head>
> </head>
> <body>
> <p>
> There are <%response.writ e(Application(" visitors"))%>
> online now!
> </p>
> </body>
> </html>[/color]

**Larry Bud** · Jul 19 '05, 01:29 PM

Re: Count of current visitors

> > I got this code, but it does not work on my server... I can open three[color=blue][color=green]
> > IE browsers and watch the count go to three. Upon closing two, each
> > having separate sessions (and session ID's of course), the count
> > remains at three! I'm not looking for alternative ways of doing this:
> > I'm interested in knowing why the application variable does not get
> > reduced upon ending the session by closing the browser. Any ideas?
> >[/color]
> This seems to be a very prevalent misconception.
>
> The session does not end when the user closes his browser. Think about it.
> How can the server know when a user closes his browser? Answer: it can't.[/color]

True, and I think people get confused because if they do close a
browser window, then open a new one, they get a new session.

**cc@cc.com** · Jul 19 '05, 01:30 PM

Re: Count of current visitors

On Mon, 2 Aug 2004 06:29:21 -0400, "Bob Barrows [MVP]"
<reb01501@NOyah oo.SPAMcom> wrote:

I've been developing on the IIS platform since '98, and I've never
needed this counter functionality before. And this caught me off
guard. OF COURSE! The browser isn't going to send a last http call
before the .exe ends, so the server won't know when it closes.

I could SWEAR I read in one of those WROX books that session ended on
closing the browser, and that kinda' stuck with me.

Anyway... what's a 20 minute delay in the scope of all the other stuff
we have to deal with.
[color=blue]
>cc@cc.com wrote:[color=green]
>> From the popular website At this link:
>> http://www.w3schools.com/asp/asp_globalasa.asp
>>
>> I got this code, but it does not work on my server... I can open three
>> IE browsers and watch the count go to three. Upon closing two, each
>> having separate sessions (and session ID's of course), the count
>> remains at three! I'm not looking for alternative ways of doing this:
>> I'm interested in knowing why the application variable does not get
>> reduced upon ending the session by closing the browser. Any ideas?
>>[/color]
>This seems to be a very prevalent misconception.
>
>The session does not end when the user closes his browser. Think about it.
>How can the server know when a user closes his browser? Answer: it can't.
>HTTP is a stateless protocol. There is no "signal" sent to the server when a
>user closes his browser, or navigates to another website. The only way a web
>server has of knowing a session is still in use is if it receives requests
>for pages with the session ID in the request headers.
>
>There are only two ways a session will end:
>
>1. A Session.Abandon statement is executed
>2. The session's timeout period is exceeded, i.e., the server receives no
>new requests for pages containing that session id for a longer period of
>time than the session's timeout setting.
>
>So, in the scenario you describe above: if your session timeout setting is
>at the default value of 20 min., the user count will get adjusted 20 min.
>after the user closes his browser.
>
>Aaron describes a way to get a more accurate count of current users using a
>database in this article:
>http://www.aspfaq.com/show.asp?id=2491
>
>HTH,
>Bob Barrows
>--
>Microsoft MVP - ASP/ASP.NET
>Please reply to the newsgroup. This email account is my spam trap so I
>don't check it very often. If you must reply off-line, then remove the
>"NO SPAM"
>
>[/color]

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