asp.net - In a multi web server farm, how does session state work? -

case 1: stateserver

<system.web>    <sessionstate     mode="stateserver"     stateconnectionstring="tcpip=127.0.0.1:42626"     sqlconnectionstring="data source=127.0.0.1;trusted_connection=yes"     cookieless="false"     timeout="20"   />  ...  </system.web> 

case 2: sql server

<sessionstate   mode="sqlserver"   stateconnectionstring="tcpip=127.0.0.1:42626"   sqlconnectionstring="data source=127.0.0.1;trusted_connection=yes"   cookieless="false"   timeout="20" />  

question: 1. in case 1 , 2 appropriate location of sql or state server have configured in web.config each of web server in farm.

2. can have servers configured state , sql?

3. can have cookieless , withcookie

4. suppose if use <sessionstate cookieless="true" />, default of modes used? can done in multiserver farm, or necessary specify ip?

1.) can have servers configured state , sql?

no, should not. suppose when user makes request, 1 of server web farm store session in stateserver. in case same user makes request ( clicking links etc...), image happen if load balancer send request 2nd web server ? there no session same user configured sqlserver mode same , session user stored on state server on first request.

2.) can have cookieless , withcookie ?

again no, similar understanding pointed above. 1 of server use cookies track session , other 1 cookieless ( hence uri ) track same session , thus, if request gets forwarded different servers, no session detected.

3.) suppose if use <sessionstate cookieless="true" />, default of modes used? can done in multiserver farm, or necessary specify ip?

understand setting: cookieless="true|false", used track session particular user between client side , server side.

the actual session data there stored on sqlserver/state server, defined in mode settings as:

<sessionstate  mode="stateserver|sqlserver" ... /> 

if don't specify mode setting, default value of inproc used.

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additional note: cookie or uri have sessionid associated them. sessionid unique string, used track individual visitor between visits website.

as result of cookieless="true", sessionid embedded in page urls. drawback you'll end ugly urls, not seo (search engine optimization) , visitor not remember it. here example url of website uses asp.net cookieless sessions:

http://samplewebsite.com/(45f8c4zyybphaw2mt3dfgnjk4j)/home.aspx

bolded part represents session id, used recognize visitor.