Where asp.net session is kept on iis server

i want to know where a session is sto开发者_运维问答red when i set it in asp.net application. Does it consume RAM or hard disk space?

Actually, i save a datatable into a session variable. I save it into session because calculation of the datatable takes long time. In order not to calculate the datatable again, i get it from the session.

But i am curious about the time when the datatable will grow much larger than now. Will it stuck the ISS?

Thanks

Session state in ASP.NET is by default stored in process memory (which is RAM).

You can change this in web.config by altering the values of the configuration/system.web/sessionState element:

<configuration>
  <system.web>
    <sessionState mode="...">
  </system.web>
</configuration>

The available options are:

• InProc (default)
• StateServer - will store in a seperate process which can be on a seperate computer
• Off
• SqlServer - will store state information in a sql server database
• Custom - allows you to provide your own session store

Depending on how you configure the Session in your Web.Config, the Session can be stored In-Memory, Asp.NET State Server, Sql Server.

By default, the session is stored in-memory, which means the Ram. If the data-table gets large and there are a number of concurrent users, you may get an exception. Depends on how many users are accessing the system concurrently, what is the Ram on your system etc.

Session state can be stored in different places that you can choose. Here's a good explanation on MSDN The default is in memory on the server where you web application runs, so if your session grows too large you will indeed have ram/paging problems.

But why session? Is the data in the datatable user-specific? Otherwise Cache would be more appropriate.

If you are using InProc session, then it will be stored in memory. So if you have enough memory it will be in memory. Once you hit your limit look forward to it paging out to disk.

You can also use out of process session storage like the SQL server. This is configurable in the web.config. Note that you will need to have a database configured for it. You can also check out MSDN to read up on the storage types.

Old link above, but still partially useful. Another quick look and I'm found a better link that goes more into detail.

The typical InProc session state is stored in memory of the web server.