C# – SessionState stateConnectionString and sqlConnectionString

asp.netcnetsql-server-2008vb.net

We want to store session in SQL Server. We have sessionState mode="SQLServer". I have been given a sample connectionstring as listed below. In this it is having both stateConnectionString and sqlConnectionString.

Question: Why do we need stateConnectionString when mode="SQLServer"?

<sessionState mode="SQLServer" 
cookieless="false" timeout="20" 
stateConnectionString="tcpip=XXX.XX.XXX.XXX:42424" 
sqlConnectionString="data source=XXX-FFFF-sql2k8,2025;
Initial   Catalog=AspState_XX_3_0;user id=XXX;password=XXX" 
allowCustomSqlDatabase="true" 
sqlCommandTimeout="1200"/>

Note 1: SQLServer mode stores session state in a SQL Server database. Using this mode ensures that session state is preserved if the Web application is restarted and also makes session state available to multiple Web servers in a Web farm. To use SQLServer mode, you must first be sure the ASP.NET session state database is installed on SQL Server. You can install the ASP.NET session state database using the Aspnet_regsql.exe tool

Note 2: StateServer mode stores session state in a process, referred to as the ASP.NET state service, that is separate from the ASP.NET worker process or IIS application pool. To use StateServer mode, you must first be sure the ASP.NET state service is running on the server used for the session store. To use StateServer mode in a Web farm, you must have the same encryption keys specified in the machineKey element of your Web configuration for all applications that are part of the Web farm.

Best Answer

AFAIK you can skip the StateConnectionString when storing sessionstate in SQL Server.

I haven't tried it, but it seems to be confirmed here: http://support.microsoft.com/kb/317604

This is the style that Microsoft tends to use in their examples.

It appears that the guidance in this area may have changed, as StyleCop now enforces the use of the C# specific aliases.

C# – the difference between const and readonly in C#

Apart from the apparent difference of

having to declare the value at the time of a definition for a const VS readonly values can be computed dynamically but need to be assigned before the constructor exits.. after that it is frozen.
const's are implicitly static. You use a ClassName.ConstantName notation to access them.

There is a subtle difference. Consider a class defined in AssemblyA.

public class Const_V_Readonly
{
  public const int I_CONST_VALUE = 2;
  public readonly int I_RO_VALUE;
  public Const_V_Readonly()
  {
     I_RO_VALUE = 3;
  }
}

AssemblyB references AssemblyA and uses these values in code. When this is compiled:

in the case of the const value, it is like a find-replace. The value 2 is 'baked into' the AssemblyB's IL. This means that if tomorrow I update I_CONST_VALUE to 20, AssemblyB would still have 2 till I recompile it.
in the case of the readonly value, it is like a ref to a memory location. The value is not baked into AssemblyB's IL. This means that if the memory location is updated, AssemblyB gets the new value without recompilation. So if I_RO_VALUE is updated to 30, you only need to build AssemblyA and all clients do not need to be recompiled.

So if you are confident that the value of the constant won't change, use a const.

public const int CM_IN_A_METER = 100;

But if you have a constant that may change (e.g. w.r.t. precision).. or when in doubt, use a readonly.

public readonly float PI = 3.14;

Update: Aku needs to get a mention because he pointed this out first. Also I need to plug where I learned this: Effective C# - Bill Wagner

Best Answer

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This is the style that Microsoft tends to use in their examples.

C# – the difference between const and readonly in C#

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