Do session variables write anything to the drive?

[MarkT]

As the subject indicates, is anything written to the users machine or are these bits of information just held in memory?

[blindlizard]

I am not sure what is written, but there is something because the user has to have session cookies enabled in their browser for session variables to work.

[Memnoch1207]

Cookies are written to the users temp directory.

[dj4uk]

A Session cookie that holds the session id is placed on the users machine.

All the Session variables are held in the memory on the web server (at least this is the case with traditional ASP not ASP.NET - I presume you are talking about standard ASP).

As the session variables are held in the servers memory it is a bad idea to hold alot of information in the Session object if there are alot of users accessing the website simultaneously.

An example of this is if you have 1Kb of Session data for each user then 10,000 simultaneous sessions would mean roughly 10,000Kb or 10Mb of info stored in the server memory.

If its only a small amount of data or small amounts of traffic on the website then using the Session would be ok. It all depends on your usage.

DJ

[abhijit]

so basically you don't need the user's browser to have the cookies enabled.

Abhijit

[blindlizard]

They have to have session cookies enabled. There are 2 settings (in IE, but I susspect all browsers) one for real persistant cookies and the other for session cookies. Sessions as dj4uk said are stored locally on the users machine. This cookie only holds the sessionid which is passed to the webserver which has all the real values that have been saved. And as dj4uk said this has changed in .Net where nothing is saved on the local machine when sessions are used.