Configure ASP.NET Core Sessions with NCache IDistributedCache Provider

You can also use ASP.NET Core sessions with NCache’s IDistributedCache Provider. ASP.NET Core provides the AddDistributedMemoryCache() method to add a default implementation of IDistributedCache. However, to utilize NCache as a distributed cache to store ASP.NET Sessions, NCache provides its own extension method, AddNCacheDistributedCache(), which adds NCache as the default distributed cache as an implementation of IDistributedCache.

Install NuGet Package

Install the NuGet package Alachisoft.NCacheSessionServices.Enterprise to your application by executing the following command in the Package Manager Console:

Install-Package Alachisoft.NCacheSessionServices.Enterprise

Include Namespaces

To utilize the APIs, include the following namespaces in your application in Startup.cs of your application:

• using Alachisoft.NCache.Web.SessionState;
• using Microsoft.AspNetCore.Hosting;

You can configure NCache as a distributed cache for your ASP.NET Core application in two steps:

1. Configuring services

2. Adding middleware to the application

Step 1: Configure Services

NCache provides the AddNCacheDistributedCache() extension method on IServiceCollection, which requires just a cache name in NCache and any optional configurations to store the sessions. The configuration object is the same as NCache ASP.NET Core Session Provider, which can be initialized similarly. The configuration can be provided through IOptions initializer as well.

Configurations specific to Distributed Caching:

Member	Type	Description	Default Value
CacheName	string (required)	Specifies the name of the cache to be used for caching session. If no cache name is specified, a configuration exception will be thrown.	-
EnableLogs	bool (optional)	If this flag is set, NCache logs all error information. The log files are created in [InstallDir]/log-files/SessionState.	false
EnableDetailLogs	bool (optional)	When this flag is set, NCache logs all debugging information. The log files are created in [InstallDir]/log-files/SessionState.	false
ExceptionsEnabled	bool (optional)	Specifies whether exceptions from cache API are propagated to the page output. Setting this flag is especially helpful during development phase of application, since exceptions provide more information about the specific causes of failure.	false
WriteExceptionsToEventLog	bool (optional)	If this flag is set, all the exceptions from cache API are written to event logs.	false

There are two methods to specify configurations:

• Through your application as IOptions or
• In JSON format in Appsettings.json of your application.

Method 1: Specifying Configurations In IOptions

The AddNCacheDistributedCache() method is an extension of the AddDistributedCache() method provided by ASP.NET Core.

public void ConfigureServices(IServiceCollection services)
{
    //Add framework services
    services.AddMvc();

    services.AddNCacheDistributedCache();

    //Add services to the container with configured session (SessionAppId = NcacheSessionApp) for cache "MySessionCache", with logging enabled and idle timeout set to 5
    services.AddNCacheSession(configuration =>
    {
        configuration.CacheName = "mySessionCache";
        configuration.EnableLogs = true;
        configuration.SessionAppId = "NCacheSessionApp";
        configuration.SessionOptions.IdleTimeout = 5;
        configuration.SessionOptions.CookieName = "AspNetCore.Session";
    });
}

Method 2: Specifying Configurations In Appsettings.json

You can either specify the configurations within your application through IOptions or in JSON format in Appsettings.json of your application.

{
  "AppSettings": {
    "SiteTitle": "ASP.NET MVC Music Store",
    "CacheDbResults": true,
    "CacheName": "mySessionCache"
  },

  "NCacheSessions": {
    "SessionAppId": null,
    "SessionOptions": {
      "CookieName": "AspNetCore.Session",
      "CookieDomain": null,
      "CookiePath": "/",
      "CookieHttpOnly": "True",
      "IdleTimeout": "5",
      "CookieSecure": "None"
    },
    "CacheName": "mySessionCache",
    "EnableLogs": "True",
    "RequestTimeout": "90"
  },
}

NCache provides the SetNCacheSessionConfiguration()method to initialize configurations from external files before adding the session services to the container. Using this method, you can refer to the configurations by providing the name of the section containing JSON format configurations in Appsettings.json:

public void ConfigureServices(IServiceCollection services)
{
    //Add framework services
    services.AddMvc();

    //Add services to the container
    services.SetNCacheSessionConfiguration(Configuration.GetSection("NCacheSettings"));                   

    services.AddNCacheDistributedCache();

    services.AddSession();
}

Step 2: Add Middleware to Application

Once the distributed cache has been added to the service, sessions can store the data in NCache. UseSession() extension method provided by ASP.NET Core will add the default session middleware to the application but will utilize NCache as its cache.

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();

    if (env.IsDevelopment()){
        app.UseDeveloperExceptionPage();
        app.UseBrowserLink();
    }
    else{
        app.UseExceptionHandler("/Home/Error");
    }

    app.UseStaticFiles();
    app.UseSession(); //enable session which will store data in NCache distributed cache
                      //which has been configured in ConfigureServices()

    app.UseMvc(routes =>
    {
        routes.MapRoute(
            name: "default",
            template: "{controller=myApp}/{action=Index}/{id?}");
    });
}