Multi-Site Sessions

NCache provides Session sharing support across multiple regions. This prevents users from losing their sessions in case you need to reroute your traffic to another location because of traffic or due to disaster recovery. Sessions are replicated across WAN seamlessly without replicating the entire session which may result in bandwidth expense. Figure 1 shows the process flow associated with session sharing across multiple regions.

Multi Region ASP.NET Session Provider in NCache

Prerequisites

To utilize ASP.NET Session State provider in your application, install the AspNet.SessionState.NCache NuGet package by executing the following command in the Package Manager Console:

Install-Package AspNet.SessionState.NCache

Add New Section for Session State Management

Modify <configSections> section in the application's Web.config and add the following section which will specify the locations and primary and secondary caches.

<configSections>
    <section name="ncache" type="Alachisoft.NCache.Web.SessionStateManagement.NCacheSection,
    Alachisoft.NCache.SessionStateManagement, Version=x.x.x.x, Culture=neutral, PublicKeyToken=CFF5926ED6A53769">
</configSections>
Note

Replace "x.x.x.x" with the version of NCache you are using.

Modify Web.Config

Add a section with the section name specified above (<ncache> in this case), under the <configuration> tag in your application's Web.config:

<ncache>
  <sessionLocation>
    <primaryCache id="London_Cache" sid-prefix="LDNC"/>
    <secondaryCache id="NewYork_Cache" sid-prefix="NYKC"/>
    <secondaryCache id="Tokyo_Cache" sid-prefix="TKYC"/>
  </sessionLocation>
</ncache>

Modify sessionState Tag

Enable custom sessionID manager using the sessionIDManagerType attribute of the sessionState element in Web.config and add custom provider.

Member Description
sessionIDManagerType Optional String attribute. Specifies an identifier to make sure that session id remains unique in case multiple applications are using the same cache. Application id should be the same for an application in a web farm. If no app id is specified, nothing will be concatenated with session id. 
<sessionState
cookieless ="false"
regenerateExpiredSessionId="true"
mode="Custom"
customProvider="NCacheSessionProvider"
timeout="60" sessionIDManagerType="Alachisoft.NCache.Web.SessionStateManagement.CustomSessionIdManager, Alachisoft.NCache.SessionStateManagement">
  <providers>
    <add name ="NCacheSessionProvider"
    type="Alachisoft.NCache.Web.SessionState.NSessionStoreProvider"
    sessionAppId="demoApp"
    cacheName="demoCache"
    writeExceptionsToEventLog="false"
    asyncSession="false"
    enableLogs="false"/>
  </providers>
</sessionState>
  • When Location Affinity is enabled, cacheName specified in <providers> section of Web.config will be ignored.
  • Cookieless sessions are not supported.

Additional Resources

NCache provides sample application for NCache ASP.NET Sessions on GitHub.