What three Session State providers are available in ASP.NET 1.1? What are the pros and cons of each?

ASP.NET provides three distinct ways to store session data for your application: in-process session state, out-of-process session state as a Windows service, and out-of-process session state in a SQL Server database. Each has it advantages.
1.In-process session-state mode
Limitations:
* When using the in-process session-state mode, session-state data is lost if aspnet_wp.exe or the application domain restarts.
* If you enable Web garden mode in the < processModel > element of the application's Web.config file, do not use in-process session-state mode. Otherwise, random data loss can occur.
Advantage:
* in-process session state is by far the fastest solution. If you are storing only small amounts of volatile data in session state, it is recommended that you use the in-process provider.
2. The State Server simply stores session state in memory when in out-of-proc mode. In this mode the worker process talks directly to the State Server
3. SQL mode, session states are stored in a SQL Server database and the worker process talks directly to SQL. The ASP.NET worker processes are then able to take advantage of this simple storage service by serializing and saving (using .NET serialization services) all objects within a client's Session collection at the end of each Web request
Both these out-of-process solutions are useful primarily if you scale your application across multiple processors or multiple computers, or where data cannot be lost if a server or process is restarted.

Is it possible to prevent a browser from caching an ASPX page?

Just call SetNoStore on the HttpCachePolicy object exposed through the Response object's Cache property, as demonstrated here:

<%@ Page Language="C#" %>


<%
Response.Cache.SetNoStore ();
Response.Write (DateTime.Now.ToLongTimeString ());
%>


SetNoStore works by returning a Cache-Control: private, no-store header in the HTTP response. In this example, it prevents caching of a Web page that shows the current time.

How does dynamic discovery work?

ASP.NET maps the file name extension VSDISCO to an HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document.
Note that VSDISCO files are disabled in the release version of ASP.NET. You can reenable them by uncommenting the line in the section of Machine.config that maps *.vsdisco to System.Web.Services.Discovery.DiscoveryRequestHandler and granting the ASPNET user account permission to read the IIS metabase. However, Microsoft is actively discouraging the use of VSDISCO files because they could represent a threat to Web server security

What are VSDISCO files?

VSDISCO files are DISCO files that support dynamic discovery of Web services. If you place the following VSDISCO file in a directory on your Web server, for example, it returns references to all ASMX and DISCO files in the host directory and any subdirectories not noted in elements:

xmlns="urn:schemas-dynamicdiscovery:disco.2000-03-17">