ASP.NET Session-State Provider Properties

Storing ASP.NET sessions in NCache requires no programming. NCache ASP.NET Session-State Provider is a custom SessionStateStoreProviderBase implementation for an ASP.NET application. To configure and fetch ASP.NET Sessions in your application, the following modifications are required.

Note

This feature is also available in NCache Professional.

ASP.NET Session State Prerequisites

Modify asp.net session state Tag

Edit your application's Web.config file and modify the <sessionState> section as given below.

<configuration>
  ...
  <sessionState cookieless="false"
                regenerateExpiredSessionId="true"
                mode="Custom"
                customProvider="NCacheSessionProvider"
                timeout="20">
    <providers>
      <add name="NCacheSessionProvider"
          type="Alachisoft.NCache.Web.SessionState.NSessionStoreProvider"
           cacheName="demoCache"
           sessionAppId="demoApp"
           useInProc="false"
           enableLogs="false"
           exceptionsEnabled="true"
           writeExceptionsToEventLog="false"
           AsyncSession="false"
           useJsonSerialization="false"
           enableSessionLocking="true"
           sessionLockingRetry="-1"
           emptySessionWhenLocked="false" />       
    </providers>

  </sessionState>
...
</configuration>

Modify MachineKey Tag for Web Farms

In the case of web farms, add the <machineKey> tag under <system.web> section. To generate ASP.NET Session IDs in the same manner on all nodes. Learn about how to generate a machine-key for a web farm: Generate a Machine Key for a Web Farm (IIS 7)

<machineKey validationKey ="A01D6E0D1A5D2A22E0854CA612FE5C5EC4AECF24"
   decryptionKey ="ACD8EBF87C4C8937" validation ="SHA1"/>

Serializing Session Objects

Before you start using NCache to store and retrieve your ASP.NET Session objects, you need to know that you can't store these objects inside the cache directly. To store these session objects inside the cache, you need to serialize them first. There are different methods you can adopt to serialize your session objects. These methods are as follows:

Binary Serialization

You can use this serialization method if you have access to the source code of the application. In this case, you have to mark all the objects (the ones you want to store inside the cache) as serializable.

Note

However, this method is obsolete as of .NET 6.0 and if you use Binary Serialization or Compact Serialization within any ASP.NET applications, they will throw an exception informing users accordingly.

NCache Compact Serialization

As an alternative to binary serialization, you can use NCache Compact Serialization to serialize your session objects. It is faster and only requires modifying your configuration files instead of modifying the source code.

The only problem with this method is that the configuration change can be a big one if the number of classes that you want to serialize is large.

JSON Serialization

If either of the serialization techniques mentioned above does not do the job for you, then you can opt for JSON serialization instead. Using this method is super fast and simple as it only requires to make a single change to your web.config file and the rest of the job is done by NCache at runtime.

You just have to set the value of the usejsonserialization flag as True. By default, the value of this flag is False.

Fetch Session Data

NCache allows viewing all session data stored in a clustered cache via the NCache Session State Module. All session data is added in the specified cache as a tagged cache item with Tag NC_ASP.net_session_data.

The previously stored session data can be fetched by the GetByTag API, which returns a dictionary populated with session IDs and associated session data stored in the cache.

var allSessionData = cache.SearchService.GetByTag(new Tag("NC_ASP.net_session_data"));

SessionState Properties

Following is the description of the different key-value pairs specified above:

Member Description
sessionAppId It is an optional string attribute that specifies an identifier to make sure that the 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 the session Id.
cacheName This is a required String attribute that specifies the name of the cache to be used for the caching session. If no cache name is specified, a configuration exception will be thrown.
enableSessionLocking An optional Boolean attribute. If this flag is set to True, the NCache Session Store Provider exclusively locks the session store item for which multiple concurrent requests are made. The default value is False.
sessionLockingRetry This is an optional Integer attribute. If enableSessionLocking is True and this integer is not less than 0, the NCache Session Store Provider will return an empty session after sessionLockingRetry, which specifies the number of retries to acquire a lock. The default value is -1.
writeExceptionsToEventLog An optional Boolean attribute. If this flag is set to True, all the exceptions from cache API are written to event logs. The default value is False.
enableLogs It is an optional Boolean attribute. When this flag is set to True, the store provider logs all error information. The log files are created in %NCHOME%\log-files\SessionStoreProvider (Windows) or /opt/ncache/log-files/SessionStoreProvider (Linux). The default value is False.
enableDetailLogs An optional Boolean attribute. When this flag is set to True, the store provider logs all debugging information. The log files are created in %NCHOME%\log-files\SessionStoreProvider (Windows) or /opt/ncache/log-files/SessionStoreProvider (Linux). The default value is False.
exceptionsEnabled This is an optional Boolean attribute that specifies whether exceptions from cache API are propagated to the page output. Setting this flag to True is especially helpful during the development phase of the application since exceptions provide more information about the specific causes of failure. The default value is False.
operationRetry It specifies the number of times the server will retry the operation, in case a connection is lost with a server while an operation is executing. Its default value is 0(zero). operationRetry
operationRetryInterval It specifies the time interval between each operation retry, in case a connection is lost with the server. Its default value is 0(zero).
usejsonserialization This is a boolean attribute. If you want to use JSON serialization for your ASP.NET Session objects, set the value of this attribute as True. By default, the value of this attribute is False.

See Also

.NET: Alachisoft.NCache.Web.SessionState namespace.