ABP VNext + Akka.NET：高并发处理与分布式计算

ABP VNext + Akka.NET：高并发处理与分布式计算 🚀

用 Actor 模型把高并发写入“分片→串行化”，把锁与竞态压力转回到代码层面的可控顺序处理；依托 Cluster.Sharding 横向扩容，Persistence 宕机可恢复，Streams 保障背压稳定吞吐；全程采用 Akka.Hosting + 显式启动 Sharding 的写法，弱化对版本特定扩展方法的耦合。⚙️

1）TL;DR ✍️

• Actor + Sharding：按实体（DeviceId/OrderId…）顺序处理，避免热点锁与竞态；横向扩容靠分片重分布。🧩
• Persistence（事件+快照）：进程挂了可回放恢复；开发期可用内存存储，生产换 SQL/PG。💾
• Streams 背压：入口 Source.Queue(..., Backpressure) + ActorRefWithAck 打通端到端背压闭环。🧯
• Akka.Hosting：ActorRegistry + IRequiredActor<T> 与 ABP/.NET 的 DI、日志无缝融合。🔌
• 两套部署路径：本地多实例（静态种子） & K8s（Akka.Management + Cluster Bootstrap）。☸️

2）适用场景 🎯

• IoT/日志/交易流水等 写多读少 且 每实体需要严格顺序 的场景；
• 需要 快速横向扩容、自动失效转移、进程级容错 的场景；
• 希望把“拓扑/容错/限流/背压”收束到应用代码表达层的团队。

3）环境与依赖 🧰

• .NET / ABP 版本矩阵

  • .NET 7 → ABP 7
  • .NET 8 → ABP 8.0+（推荐）

• NuGet（核心）
  Akka, Akka.Hosting, Akka.Cluster, Akka.Cluster.Sharding,
  Akka.Persistence.Sql, Akka.Streams, Akka.Logger.Serilog, Akka.Serialization.Hyperion

• 可选（K8s/管理）
  Akka.Management, Akka.Discovery.KubernetesApi

<ItemGroup>
  <PackageReference Include="Akka" Version="1.5.*" />
  <PackageReference Include="Akka.Hosting" Version="1.5.*" />
  <PackageReference Include="Akka.Cluster" Version="1.5.*" />
  <PackageReference Include="Akka.Cluster.Sharding" Version="1.5.*" />
  <PackageReference Include="Akka.Persistence.Sql" Version="1.5.*" />
  <PackageReference Include="Akka.Streams" Version="1.5.*" />
  <PackageReference Include="Akka.Logger.Serilog" Version="1.5.*" />
  <PackageReference Include="Akka.Serialization.Hyperion" Version="1.5.*" />
  <PackageReference Include="Akka.Management" Version="1.5.*" />
  <PackageReference Include="Akka.Discovery.KubernetesApi" Version="1.5.*" />
</ItemGroup>

4）目标架构与数据流（总览图）🗺️

5）最小可跑骨架（单节点，内存持久化）🏃‍♂️

先5分钟跑通闭环（不依赖外部 DB），再切换到 SQL/PG。

5.1 消息与分片提取器（稳定哈希）🔑

// Messages.cs
public interface IDeviceMsg { string DeviceId { get; } }
public sealed record Ingest(string DeviceId, double Value, DateTimeOffset Timestamp) : IDeviceMsg;
public sealed record GetCurrent(string DeviceId) : IDeviceMsg;
public sealed record CurrentState(string DeviceId, double Avg, long Count);

// 使用稳定的 HashCodeMessageExtractor，避免 string.GetHashCode() 的跨进程随机化
using Akka.Cluster.Sharding;
public sealed class DeviceMessageExtractor : HashCodeMessageExtractor
{
    public DeviceMessageExtractor(int shards) : base(shards) { }
    public override string EntityId(object message) => ((IDeviceMsg)message).DeviceId;
    public override object EntityMessage(object message) => message;
}

5.2 实体 Actor（顺序处理 + 快照 + 钝化）🧠

// DeviceEntityActor.cs
using Akka.Actor;
using Akka.Event;
using Akka.Persistence;
using Akka.Cluster.Sharding;

public sealed class DeviceEntityActor : ReceivePersistentActor
{
    private readonly ILoggingAdapter _log = Context.GetLogger();
    private double _sum; private long _count;

    public override string PersistenceId { get; }

    public DeviceEntityActor()
    {
        var entityId = Self.Path.Name;          // Sharding 注入
        PersistenceId = $"device-{entityId}";

        Command<Ingest>(cmd =>
        {
            Persist(cmd, e =>
            {
                _sum += e.Value; _count++;
                if (_count % 1000 == 0) SaveSnapshot((_sum, _count));
            });
        });

        Command<GetCurrent>(q =>
        {
            var avg = _count == 0 ? 0 : _sum / _count;
            Sender.Tell(new CurrentState(q.DeviceId, avg, _count));
        });

        // 自动钝化：与 remember-entities 互斥（见“生产配置”）
        Context.SetReceiveTimeout(TimeSpan.FromMinutes(5));
        Receive<ReceiveTimeout>(_ => Context.Parent.Tell(new Passivate(PoisonPill.Instance)));

        Recover<Ingest>(e => { _sum += e.Value; _count++; });
        Recover<SnapshotOffer>(s =>
        {
            var (sum, cnt) = ((double, long))s.Snapshot;
            _sum = sum; _count = cnt;
        });
    }
}

5.3 Streams 入口 + ACK 闭环（ActorRefWithAck）🔁

// Ingress messages for ACK protocol
public sealed record StreamInit();
public sealed record StreamAck();
public sealed record StreamComplete();
public sealed record StreamFail(Exception Cause);

// IngressActor.cs
using Akka.Actor;
using Akka.Cluster.Sharding;

public sealed class IngressActor : ReceiveActor
{
    private readonly IActorRef _region;

    public IngressActor(IActorRef region)
    {
        _region = region;

        Receive<StreamInit>(_ => Sender.Tell(new StreamAck()));         // 握手
        Receive<Ingest>(msg => { _region.Tell(msg); Sender.Tell(new StreamAck()); }); // 逐条ACK
        Receive<StreamComplete>(_ => Context.Stop(Self));
        Receive<StreamFail>(x => { Context.GetLogger().Error(x.Cause, "stream failed"); });
    }
}

// Streams wiring（Program/Module中）
using Akka.Streams;
using Akka.Streams.Dsl;

// 1) Materializer
var mat = SystemMaterializer.Get(system).Materializer;

// 2) Source.Queue：入口背压队列
var (queue, source) = Source
  .Queue<Ingest>(bufferSize: 10_000, OverflowStrategy.Backpressure)
  .PreMaterialize(mat);

// 3) 将流量通过 ActorRefWithAck 打给 IngressActor（由其负责ACK并Tell到Region）
var ingress = system.ActorOf(Props.Create(() => new IngressActor(region)), "ingress");

var ackSink = Sink.ActorRefWithAck<Ingest>(
    target: ingress,
    onInitMessage: new StreamInit(),
    ackMessage: new StreamAck(),
    onCompleteMessage: new StreamComplete(),
    onFailureMessage: ex => new StreamFail(ex)
);

// 4) 可选：分组/聚合后下发
source
  .GroupBy(1024, x => x.DeviceId)
  .GroupedWithin(500, TimeSpan.FromMilliseconds(50))
  .MergeSubstreams()
  .SelectMany(batch => batch) // 批内可先聚合降噪，再下发
  .RunWith(ackSink, mat);

// 在 ABP 层/Controller 中：await queue.OfferAsync(new Ingest(deviceId, value, DateTimeOffset.UtcNow));

5.3.1 端到端背压闭环 🧨

5.4 Akka.Hosting：显式启动 Sharding + DI 注入 🧩

// Program.cs / YourAbpModule.ConfigureServices(...)
using Akka.Actor;
using Akka.Cluster.Sharding;
using Akka.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

// Marker type for ActorRegistry (避免直接暴露 ActorRef 原型类型)
public sealed class DeviceRegionKey {}

builder.Services.AddAkka("AppSystem", (akka, sp) =>
{
    // —— 统一日志到 Serilog ——
    akka.ConfigureLoggers(l =>
    {
        l.ClearLoggers();
        l.AddLogger<Akka.Logger.Serilog.SerilogLogger>();
    });

    // —— 开发环境：内存持久化（复制即可跑）——
    var devHocon = """
    akka {
      loglevel = "INFO"
      actor {
        provider = "cluster"
        default-mailbox {
          mailbox-type = "Akka.Dispatch.BoundedMailbox"
          mailbox-capacity = 20000
          mailbox-push-timeout-time = 2s
        }
        serializers {
          hyperion = "Akka.Serialization.HyperionSerializer, Akka.Serialization.Hyperion"
        }
      }
      remote.dot-netty.tcp { hostname = "0.0.0.0", port = 4053 }
      cluster { seed-nodes = ["akka.tcp://AppSystem@localhost:4053"], roles = ["api"] }
      persistence {
        journal.plugin = "akka.persistence.journal.inmem"
        snapshot-store.plugin = "akka.persistence.snapshot-store.inmem"
      }
      cluster.sharding { passivate-idle-entity-after = 5 m }
    }
    """;
    akka.AddHocon(devHocon, HoconAddMode.Append);

    // —— 显式启动 Sharding 并注入 Region —— 
    akka.WithActors((system, registry) =>
    {
        var sharding  = ClusterSharding.Get(system);
        var settings  = ClusterShardingSettings.Create(system);
        var region = sharding.Start(
            typeName: "device-entity",
            entityProps: Props.Create(() => new DeviceEntityActor()),
            settings: settings,
            messageExtractor: new DeviceMessageExtractor(shards: 64)
        );

        registry.TryRegister<DeviceRegionKey>(region);

        var ingress = system.ActorOf(Props.Create(() => new IngressActor(region)), "ingress");
        registry.TryRegister<IngressActor>(ingress);
    });
});

6）与 ABP 应用层对接（IRequiredActor + Ask/Tell）🔗

// DeviceAppService.cs
using Akka.Actor;
using Akka.Hosting;
using Microsoft.Extensions.Configuration;
using Volo.Abp.Application.Services;

public class DeviceAppService : ApplicationService
{
    private readonly IActorRef _region;
    private readonly IActorRef _ingress;
    private readonly TimeSpan _askTimeout;

    public DeviceAppService(IRequiredActor<DeviceRegionKey> region,
                            IRequiredActor<IngressActor> ingress,
                            IConfiguration cfg)
    {
        _region = region.ActorRef;
        _ingress = ingress.ActorRef;
        _askTimeout = TimeSpan.FromSeconds(cfg.GetValue("Akka:AskTimeoutSeconds", 2));
    }

    // 写多：走 Streams 队列 -> IngressActor（ACK背压闭环）
    public async Task IngestAsync(string deviceId, double value)
    {
        _ingress.Tell(new Ingest(deviceId, value, DateTimeOffset.UtcNow));
        await Task.CompletedTask;
    }

    // 查少：必要时 Ask（统一超时/重试策略）
    public Task<CurrentState> GetAsync(string deviceId)
        => _region.Ask<CurrentState>(new GetCurrent(deviceId), _askTimeout);
}

7）生产切换：SQL Server 持久化 🧱

开发用内存持久化；生产切换到 SQL/PG。以 SQL Server 为例（同理可替换为 PostgreSQL/MySQL，对应 provider-name 也要换成各自 Linq2Db ProviderName）。

# appsettings.Production.hocon（或用 AddHocon Append）
akka {
  persistence {
    journal {
      plugin = "akka.persistence.journal.sql"
      sql {
        class = "Akka.Persistence.Sql.Journal.SqlWriteJournal, Akka.Persistence.Sql"
        connection-string = "Server=localhost;Database=AkkaDemo;User Id=sa;Password=Your_password123;"
        provider-name = "SqlServer.2019"
      }
    }
    snapshot-store {
      plugin = "akka.persistence.snapshot-store.sql"
      sql {
        class = "Akka.Persistence.Sql.Snapshot.SqlSnapshotStore, Akka.Persistence.Sql"
        connection-string = "Server=localhost;Database=AkkaDemo;User Id=sa;Password=Your_password123;"
        provider-name = "SqlServer.2019"
      }
    }
  }

  # 生产常见：开启记忆实体，禁用自动钝化
  cluster.sharding {
    remember-entities = on
    # passivate-idle-entity-after 将被自动禁用
  }
}

⚠️ 上线前：按官方脚本初始化 Journal/Snapshot 架构与索引；
Remember-Entities × 钝化：开启 remember-entities=on 会禁用自动钝化；需要停用实体，请用 Passivate 显式停止并取消记忆。🧹

8）序列化与安全（Hyperion）🛡️

akka.actor {
  serializers {
    hyperion = "Akka.Serialization.HyperionSerializer, Akka.Serialization.Hyperion"
  }
  # 建议只绑定到你的消息基类型，而不是 System.Object
  serialization-bindings {
    "Your.Namespace.IDeviceMsg, Your.Assembly" = hyperion
  }
  serialization-settings.hyperion {
    # 需要时可开启版本容忍、已知类型等（示例）
    # version-tolerance = on
    # knownTypesProvider = "Your.Namespace.KnownTypesProvider, Your.Assembly"
  }
}

只绑定消息基类型，避免误序列化；若强 Schema 演进诉求，生产可切 Protobuf。📦

9）Actor 生命周期 🧬

10）Sharding 重分布 📦

11）K8s 拓扑 ☸️

12）可靠性与容错 🛠️

• 监督策略：业务可恢复异常 Resume；不可恢复 Restart/Stop；
• 幂等：命令带 CommandId，Actor 内滑窗去重；
• 熔断：外部调用 Actor 使用 CircuitBreaker；
• 死信监控：订阅 DeadLetter 输出到 Serilog（报警）。📣

13）可观测性与日志 📊

• Akka.Logger.Serilog 与 ABP 的 Serilog 统一；
• 日志添加 SourceContext=ActorPath 维度，便于过滤；
• 定期拉取 GetClusterShardingStats、GetShardRegionState 观测分布/热点；
• 流水线指标：入口队列深度、批量大小、吞吐/延迟、失败率（Prometheus/OpenTelemetry）。

14）部署：本地多实例 & K8s 🧪

本地/Compose

• 多进程/容器静态 seed-nodes；
• 验证分片重分布、Failover、恢复时间（含快照前后对比）。

Kubernetes

• Akka.Management + Akka.Discovery.KubernetesApi 做 Cluster Bootstrap；
• roles=["api"] / ["worker"] 分层，worker 走 HPA；
• 健康探针 + Coordinated Shutdown，滚动升级/金丝雀发布。🌈

15）性能调优清单 ⚡

1. 分片数：初始 = 总核数 × 2~4，压测校正（过小→热点，过大→开销增）。
2. 消息体：短小定长；大对象走外部存储，仅传引用。
3. 快照频率：以“重放时长目标（如 <2s）”反推，起步 500~2000 事件/快照。
4. Ask 慎用：统一超时/重试策略；写多路径优先 Tell。
5. 邮箱一律有界；热点实体可专用 dispatcher/邮箱。
6. 背压闭环：优先 ActorRefWithAck；配合节流/并行度/批量。

16）常见坑 & 规避 🧨

• ❌ string.GetHashCode() 做分片哈希 → ✅ 用 HashCodeMessageExtractor（稳定）。
• ❌ Streams 直接 Tell 到 Region → ✅ 用 ActorRefWithAck/批量 Ask 打通背压闭环。
• ❌ System.Object 绑定 Hyperion → ✅ 只绑定消息基类型，并考虑白名单/演进。
• ❌ Remember-Entities 开启仍指望自动钝化 → ✅ 自动钝化被禁用；需要停用时用 Passivate。
• ❌ 无界邮箱 → ✅ 一律有界并观测队列深度。
• ❌ 乱配 ABP×.NET → ✅ .NET 8 对应 ABP 8+。