ABP VNext + 多级缓存架构：本地 + Redis + CDN

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一、引言 🚀

✨ TL;DR

• 🔥 本地内存 Cache + Redis 分布式 Cache（HybridCache）+ CDN 静态资源三级缓存
• ⚙️ 演示 Cache-Aside、Write-Through、Write-Behind、分布式锁、版本管理、失效广播
• 📈 端到端示例：API 数据与静态资源协同优化

📚 背景与动机
在微服务环境中，单一内存缓存仅限单实例；纯 Redis 缓存易遭“击穿/雪崩”；静态资源如不加速则带宽受限。三级缓存架构结合本地缓存的超低延迟、Redis 的跨节点共享和 CDN 的全球分发，可实现秒级响应与高可用。

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二、环境与依赖 🛠️

• 运行平台：.NET 6+ / ABP VNext 6.x

• NuGet 包：

  • Microsoft.Extensions.Caching.Memory（内存缓存）
  • Microsoft.Extensions.Caching.StackExchangeRedis（分布式缓存）
  • Volo.Abp.Caching.StackExchangeRedis（ABP Redis 扩展）
  • Volo.Abp.DistributedLocking + Volo.Abp.DistributedLocking.Redis（分布式锁）
  • Microsoft.Extensions.Caching.Hybrid + Volo.Abp.Caching.Hybrid（HybridCache）
  • AspNetCore.HealthChecks.Redis（Redis 健康检查）
  • Prometheus.AspNetCore.HealthChecks（Prometheus 转发）
  • Testcontainers + Testcontainers.Redis（集成测试）

• CDN 服务示例：Azure CDN / Cloudflare / AWS CloudFront

• 配置示例（appsettings.json）

  "Caching": {"Memory": { "SizeLimit": 1024 },"Redis": { "Configuration": "localhost:6379,abortConnect=false" },"DistributedLock": { "KeyPrefix": "MyApp:" },"HybridCache": {"GlobalHybridCacheEntryOptions": {"Expiration": "00:20:00","LocalCacheExpiration": "00:10:00"}},"Cdn": {"Enable": true,"BaseUrl": "https://cdn.example.com/","StaticPaths": ["/images","/css","/js"]}
  }
  

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三、架构概览 🌐

🔍 四级职责

1. 🧠 本地缓存：超低延迟、单节点热点数据
2. 🤝 混合缓存：IHybridCache<T> 自动同步本地与分布式
3. 🔴 Redis：跨实例共享、高容量、高可用（由 HybridCache 隐式使用）
4. ☁️ CDN：全球边缘分发、静态资源加速

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请求全链路示意 🛣️

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四、本地内存缓存层 🧠

📦 注入&配置

services.AddMemoryCache(options =>
{options.SizeLimit = 1024;
});

💡 Cache-Aside 示例

if (!_memory.TryGetValue(key, out T data))
{data = await next();_memory.Set(key, data, new MemoryCacheEntryOptions{AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(5),SlidingExpiration = TimeSpan.FromMinutes(2),Size = 1,Priority = CacheItemPriority.High});
}
return data;

• 线程安全：IMemoryCache 支持并发访问，但需注意服务生命周期

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五、分布式锁提供者注册 🔐

// 在 Module.ConfigureServices 或 Startup.ConfigureServices 中：
services.AddStackExchangeRedisLocking(opts =>
{opts.Configuration = Configuration["Caching:Redis:Configuration"];opts.KeyPrefix = Configuration["DistributedLock:KeyPrefix"];
});

• 确保锁在多实例下跨节点生效，防止 Cache Stampede

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六、HybridCache：二级缓存一体化 🤝

📦 注入 & 配置

builder.Services.AddHybridCache(); 
Configure<AbpHybridCacheOptions>(options =>
{options.GlobalHybridCacheEntryOptions = new HybridCacheEntryOptions{Expiration = TimeSpan.FromMinutes(20),LocalCacheExpiration = TimeSpan.FromMinutes(10)};
});

🔄 使用示例

var item = await _hybridCache.GetOrCreateAsync(key,async () => await LoadFromDbAsync(),() => new HybridCacheEntryOptions{Expiration = TimeSpan.FromMinutes(20),LocalCacheExpiration = TimeSpan.FromMinutes(10)});

• 背后自动尝试本地→Redis→DB，更新时自动广播失效

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七、CDN 静态资源加速 ☁️

⚙️ Cache-Control

app.UseStaticFiles(new StaticFileOptions
{OnPrepareResponse = ctx =>ctx.Context.Response.Headers["Cache-Control"] = "public,max-age=31536000"
});

🚀 Azure CLI 全量失效

- run: |az login --service-principal -u ${{ secrets.AZ_USER }} -p ${{ secrets.AZ_PASS }} --tenant ${{ secrets.AZ_TENANT }}az cdn endpoint purge \--resource-group MyRg \--profile-name MyCdnProfile \--name MyEndpoint \--content-paths '/*'

💡 PowerShell

Clear-AzCdnEndpointContent -ResourceGroupName MyRg -ProfileName MyCdnProfile `-EndpointName MyEndpoint -ContentPath @("/*","/css/*","/js/*")

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八、一致性与防护 🛡️

• 锁重试/回退：锁超时后，可短期自旋或直接回退 DB，保证可用性
• Write-Through/Write-Behind：按业务需求选型

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九、序列化与性能 ⚙️

• JSON vs MessagePack：

  • JSON 易用但体积大
  • MessagePack 紧凑高效

• 示例：

  services.AddStackExchangeRedisCache(opts =>
  {opts.Configuration = Configuration["Caching:Redis:Configuration"];
  })
  .AddStackExchangeRedisExtensions<MsgPackSerializer>();
  

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十、失效管理与版本控制 🔄

• 📅 绝对 vs 滑动过期：防止缓存雪崩或冷数据长期占用

• 🎯 Tag-based Invalidation：

  await _hybridCache.RemoveByTagAsync("Products");
  

• 🔧 版本号策略：在 Key/URL 中嵌入版本号（如 v2），发布时全量失效

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十一、监控与可观察性 📊

📈 Health Checks & Prometheus

services.AddHealthChecks().AddRedis(Configuration["Caching:Redis:Configuration"], name: "Redis").AddCheck<MemoryHealthCheck>("Memory").ForwardToPrometheus();
app.UseEndpoints(endpoints =>
{endpoints.MapHealthChecks("/healthz");endpoints.MapMetrics(); // Prometheus /metrics
});

• 需引用 Prometheus.AspNetCore.HealthChecks

🩺 OpenTelemetry & Metrics

builder.Services.AddOpenTelemetryMetrics(m =>
{m.AddAspNetCoreInstrumentation().AddHttpClientInstrumentation().AddPrometheusExporter();
});

• 在 /metrics 端点采集 Cache Hit/Miss、延迟指标，用 Grafana 可视化

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十二、多区域与高可用 🌍

• 被动 Geo-Replication（Premium）：主从同步，仅主写
• 主动 Geo-Replication（Enterprise）：多主写入，CRDT 同步

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十三、自动化测试与 CI/CD 🧪

📦 Testcontainers + xUnit

public class RedisFixture : IAsyncLifetime
{public IConnectionMultiplexer Connection { get; private set; }private readonly RedisTestcontainer _container =new TestcontainersBuilder<RedisTestcontainer>().WithDatabase(new RedisTestcontainerConfiguration { Image = "redis:7.0" }).WithWaitStrategy(Wait.ForUnixContainer().UntilPortIsAvailable(6379)).Build();public async Task InitializeAsync(){await _container.StartAsync();Connection = await ConnectionMultiplexer.ConnectAsync(_container.ConnectionString);}public async Task DisposeAsync()=> await _container.DisposeAsync();
}[CollectionDefinition("Redis")]
public class RedisCollection : ICollectionFixture<RedisFixture> { }public class CacheTests : IClassFixture<RedisFixture>
{private readonly IConnectionMultiplexer _conn;public CacheTests(RedisFixture fixture) => _conn = fixture.Connection;[Fact]public async Task GetOrAdd_Should_Cache(){var db = _conn.GetDatabase();await db.StringSetAsync("key", "value");Assert.Equal("value", await db.StringGetAsync("key"));}
}

🚄 CI/CD 示意：

• GitHub Actions：构建 → 单元/集成测试 → 发布 NuGet
• 静态资源打 Hash → 上传 Azure Blob → az cdn endpoint purge

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十四、端到端示例 🔧

public class ProductService : ApplicationService
{private readonly IMemoryCache _memory;private readonly IHybridCache<ProductDto> _hybrid;private readonly IRepository<Product, Guid> _repo;public ProductService(IMemoryCache memory,IHybridCache<ProductDto> hybrid,IRepository<Product, Guid> repo){_memory = memory;_hybrid = hybrid;_repo = repo;}public async Task<ProductDto> GetAsync(Guid id){var key = $"product:{id}";// 1️⃣ 本地缓存if (_memory.TryGetValue(key, out ProductDto dto))return dto;// 2️⃣ 混合缓存 + 分布式锁dto = await _hybrid.GetOrCreateAsync(key,async () => await MapAsync(await _repo.GetAsync(id)),() => new HybridCacheEntryOptions { Expiration = TimeSpan.FromMinutes(10), LocalCacheExpiration = TimeSpan.FromMinutes(5) });// 3️⃣ 写回本地_memory.Set(key, dto, new MemoryCacheEntryOptions { AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(5), Size = 1 });return dto;}
}

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