分布式缓存NCache使用

NCache作为缓存优点币Redis有优势，但是收费的所以选用的不多吧。下面简单实操一下：

首先官网下载组件NCache Download Center (alachisoft.com)，这里选择企业和专业版都可以，都只有一个月试用期，下一步后统一协议，后弹出第二个界面需要填写一下注册信息。重点是workemail，这里需要工作邮箱，后缀是qq，163的都不行。我用的是zoho的邮箱。

下载完毕后需要通过cmd管理员命令去安装msi的文件，因为msi不能通过右键管理员来执行，二这个必须要管理员权限（有疑问 搜索管理员身份运行msi安装），安装过程中需要安装key，注册的邮箱里面有这个。

安装完后会有这几个出现在开始菜单，只需要打开NCache Web Manager,可以打开localhost:8251的管理界面。Cache Name和Servers需要在代码和配置文件中做好配置。

下面新建netcore6 webapi程序，导入NCache的包会自动生成：client.ncconf和config.ncconf两个配置文件，重点修改client.ncconf文件的两处服务ip，还有代码

configuration.CacheName = "ClusteredCache"; 指定CacheName名称为上图的Cache Name。

using Alachisoft.NCache.Caching.Distributed;
using Microsoft.Extensions.Caching.Distributed;
using Microsoft.Extensions.Caching.SqlServer;
using Microsoft.Extensions.Caching.StackExchangeRedis;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddRazorPages();

builder.Services.AddNCacheDistributedCache(configuration =>
{
    configuration.CacheName = "ClusteredCache";
    configuration.EnableLogs = true;
    configuration.ExceptionsEnabled = true;
});

var app = builder.Build();

#region snippet_Configure
app.Lifetime.ApplicationStarted.Register(() =>
{
    var currentTimeUTC = DateTime.UtcNow.ToString();
    byte[] encodedCurrentTimeUTC = System.Text.Encoding.UTF8.GetBytes(currentTimeUTC);
    var options = new DistributedCacheEntryOptions()
        .SetSlidingExpiration(TimeSpan.FromSeconds(20));
    app.Services.GetService<IDistributedCache>()
                              .Set("cachedTimeUTC", encodedCurrentTimeUTC, options);
});
#endregion

if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapRazorPages();

app.Run();

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Caching.Distributed;
using System.Text;

namespace SampleApp.Pages
{
    #region snippet_IndexModel
    public class IndexModel : PageModel
    {
        private readonly IDistributedCache _cache;

        public IndexModel(IDistributedCache cache)
        {
            _cache = cache;
        }

        public string? CachedTimeUTC { get; set; }
        public string? ASP_Environment { get; set; }

        public async Task OnGetAsync()
        {
            CachedTimeUTC = "Cached Time Expired";
            var encodedCachedTimeUTC = await _cache.GetAsync("cachedTimeUTC");

            if (encodedCachedTimeUTC != null)
            {
                CachedTimeUTC = Encoding.UTF8.GetString(encodedCachedTimeUTC);
            }

            ASP_Environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
            if (String.IsNullOrEmpty(ASP_Environment))
            {
                ASP_Environment = "Null, so Production";
            }
        }

        public async Task<IActionResult> OnPostResetCachedTime()
        {
            var currentTimeUTC = DateTime.UtcNow.ToString();
            byte[] encodedCurrentTimeUTC = Encoding.UTF8.GetBytes(currentTimeUTC);
            var options = new DistributedCacheEntryOptions()
                .SetSlidingExpiration(TimeSpan.FromSeconds(20));
            await _cache.SetAsync("cachedTimeUTC", encodedCurrentTimeUTC, options);

            return RedirectToPage();
        }
    }
    #endregion
}

运行效果图如下：

示例代码：

exercise/NCacheDistCache at master · liuzhixin405/exercise (github.com)

参考来源：

ASP.NET Core 中的分布式缓存 | Microsoft Docs