使用分布式锁解决并发问题

src/HelloShop.AppHost/DaprComponents/redis-lock.yaml

@@ -0,0 +1,15 @@
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: lockstore
+spec:
+  type: lock.redis
+  version: v1
+  metadata:
+  - name: redisHost
+    secretKeyRef:
+       name: ConnectionStrings__cache
+  - name: redisPassword
+    value: ""
+auth:
+  secretStore: env-secretstore

src/HelloShop.AppHost/Program.cs

@@ -6,7 +6,7 @@ using Aspire.Hosting.Dapr;
 
 var builder = DistributedApplication.CreateBuilder(args);
 
-var cache = builder.AddRedis("cache", port: 6379);
+var cache = builder.AddRedis("cache", port: 6380).WithPersistence();
 
 var rabbitmq = builder.AddRabbitMQ("rabbitmq").WithManagementPlugin();
 
@@ -19,14 +19,14 @@ var orderingService = builder.AddProject<Projects.HelloShop_OrderingService>("or
     .WithReference(identityService)
     .WithDaprSidecar(options =>
     {
-        options.WithOptions(daprSidecarOptions).WithReference(rabbitmq);
+        options.WithOptions(daprSidecarOptions).WithReference(rabbitmq).WithReference(cache);
     });
 
 var productService = builder.AddProject<Projects.HelloShop_ProductService>("productservice")
     .WithReference(identityService)
     .WithDaprSidecar(options =>
     {
-        options.WithOptions(daprSidecarOptions).WithReference(rabbitmq);
+        options.WithOptions(daprSidecarOptions).WithReference(rabbitmq).WithReference(cache);
     }); ;
 
 var basketService = builder.AddProject<Projects.HelloShop_BasketService>("basketservice")
@@ -34,7 +34,7 @@ var basketService = builder.AddProject<Projects.HelloShop_BasketService>("basket
     .WithReference(cache)
     .WithDaprSidecar(options =>
     {
-        options.WithOptions(daprSidecarOptions).WithReference(rabbitmq);
+        options.WithOptions(daprSidecarOptions).WithReference(rabbitmq).WithReference(cache);
     });
 
 var apiservice = builder.AddProject<Projects.HelloShop_ApiService>("apiservice")

src/HelloShop.OrderingService/HelloShop.OrderingService.http

@@ -2,7 +2,7 @@
 
 POST {{HelloShop.OrderingService_HostAddress}}/api/orders
 Content-Type: application/json
-x-request-id: 5ddc1737-6a31-4b4f-bccd-63d0966348a1
+x-request-id: 8ddc1737-6a31-4b4f-bccd-63d0966348a1
 Authorization : Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYW1laWQiOiIxIiwidW5pcXVlX25hbWUiOiJhZG1pbiIsInJvbGVpZCI6IjEiLCJuYmYiOjE3MjA1NzY3NDYsImV4cCI6MTc0MjYwODc0NiwiaWF0IjoxNzIwNTc2NzQ2fQ.ju_D3zeGLKqJYVckbb8Y3yNkp40nOqRAJrdOsISs4d4
 
 {

src/HelloShop.ProductService/DistributedEvents/EventHandling/OrderAwaitingValidationDistributedEventHandler.cs

@@ -5,13 +5,16 @@ using HelloShop.ProductService.DistributedEvents.Events;
 using HelloShop.ProductService.Entities.Products;
 using HelloShop.ProductService.Infrastructure;
 using HelloShop.ServiceDefaults.DistributedEvents.Abstractions;
+using HelloShop.ServiceDefaults.DistributedLocks;
 
 namespace HelloShop.ProductService.DistributedEvents.EventHandling
 {
-    public class OrderAwaitingValidationDistributedEventHandler(ProductServiceDbContext dbContext, IDistributedEventBus distributedEventBus, ILogger<OrderAwaitingValidationDistributedEventHandler> logger) : IDistributedEventHandler<OrderAwaitingValidationDistributedEvent>
+    public class OrderAwaitingValidationDistributedEventHandler(ProductServiceDbContext dbContext, IDistributedEventBus distributedEventBus, IDistributedLock distributedLock, ILogger<OrderAwaitingValidationDistributedEventHandler> logger) : IDistributedEventHandler<OrderAwaitingValidationDistributedEvent>
     {
         public async Task HandleAsync(OrderAwaitingValidationDistributedEvent @event)
         {
+            await using var lockResult = await distributedLock.LockAsync("stock");
+
             logger.LogInformation("Handling distributed event {EventId} {Event}", @event.Id, @event);
 
             var confirmedOrderStockItems = new Dictionary<int, bool>();

src/HelloShop.ProductService/DistributedEvents/EventHandling/OrderPaidDistributedEventHandler.cs

@@ -5,13 +5,16 @@ using HelloShop.ProductService.DistributedEvents.Events;
 using HelloShop.ProductService.Entities.Products;
 using HelloShop.ProductService.Infrastructure;
 using HelloShop.ServiceDefaults.DistributedEvents.Abstractions;
+using HelloShop.ServiceDefaults.DistributedLocks;
 
 namespace HelloShop.ProductService.DistributedEvents.EventHandling
 {
-    public class OrderPaidDistributedEventHandler(ProductServiceDbContext dbContext) : IDistributedEventHandler<OrderPaidDistributedEvent>
+    public class OrderPaidDistributedEventHandler(ProductServiceDbContext dbContext, IDistributedLock distributedLock) : IDistributedEventHandler<OrderPaidDistributedEvent>
     {
         public async Task HandleAsync(OrderPaidDistributedEvent @event)
         {
+            await using var lockResult = await distributedLock.LockAsync("stock");
+
             foreach (var orderStockItem in @event.OrderStockItems)
             {
                 var product = await dbContext.Set<Product>().FindAsync(orderStockItem.ProductId) ?? throw new Exception($"Product with id {orderStockItem.ProductId} not found");

src/HelloShop.ProductService/Program.cs

@@ -5,6 +5,7 @@ using HelloShop.ProductService.Constants;
 using HelloShop.ProductService.Infrastructure;
 using HelloShop.ServiceDefaults.DistributedEvents.Abstractions;
 using HelloShop.ServiceDefaults.DistributedEvents.DaprBuildingBlocks;
+using HelloShop.ServiceDefaults.DistributedLocks;
 using HelloShop.ServiceDefaults.Extensions;
 using Microsoft.EntityFrameworkCore;
 
@@ -29,6 +30,7 @@ builder.Services.AddModelMapper().AddModelValidator();
 builder.Services.AddLocalization().AddPermissionDefinitions();
 builder.Services.AddAuthorization().AddRemotePermissionChecker().AddCustomAuthorization();
 builder.AddDaprDistributedEventBus().AddSubscriptionFromAssembly();
+builder.Services.AddSingleton<IDistributedLock, DaprDistributedLock>();
 // End addd extensions services to the container.
 
 var app = builder.Build();

src/HelloShop.ProductService/WeatherForecast.cs

@@ -1,15 +0,0 @@
-// Copyright (c) HelloShop Corporation. All rights reserved.
-// See the license file in the project root for more information.
-
-namespace HelloShop.ProductService;
-
-public class WeatherForecast
-{
-    public DateOnly Date { get; set; }
-
-    public int TemperatureC { get; set; }
-
-    public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);
-
-    public string? Summary { get; set; }
-}

src/HelloShop.ServiceDefaults/DistributedLocks/DaprDistributedLock.cs

@@ -0,0 +1,29 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using Dapr.Client;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HelloShop.ServiceDefaults.DistributedLocks
+{
+    public class DaprDistributedLock(DaprClient daprClient) : IDistributedLock
+    {
+        public async Task<IDistributedLockResult> LockAsync(string resourceId, int expiryInSeconds = default, CancellationToken cancellationToken = default)
+        {
+            expiryInSeconds = expiryInSeconds == default ? 60 : expiryInSeconds;
+
+            string? lockOwner = new StackTrace().GetFrame(1)?.GetMethod()?.DeclaringType?.Name;
+
+#pragma warning disable CS0618 
+            TryLockResponse response = await daprClient.Lock("lockstore", resourceId, lockOwner, expiryInSeconds, cancellationToken);
+#pragma warning restore CS0618
+
+            return new DaprDistributedLockResult(response);
+        }
+    }
+}

src/HelloShop.ServiceDefaults/DistributedLocks/DaprDistributedLockResult.cs

@@ -0,0 +1,23 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using Dapr.Client;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HelloShop.ServiceDefaults.DistributedLocks
+{
+#pragma warning disable CS0618
+    public class DaprDistributedLockResult(TryLockResponse tryLockResponse) : IDistributedLockResult
+#pragma warning restore CS0618
+    {
+        public async ValueTask DisposeAsync()
+        {
+            await tryLockResponse.DisposeAsync().ConfigureAwait(false);
+            GC.SuppressFinalize(this);
+        }
+    }
+}

src/HelloShop.ServiceDefaults/DistributedLocks/IDistributedLock.cs

@@ -0,0 +1,16 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HelloShop.ServiceDefaults.DistributedLocks
+{
+    public interface IDistributedLock
+    {
+        public abstract Task<IDistributedLockResult> LockAsync(string resourceId, int expiryInSeconds = default, CancellationToken cancellationToken = default);
+    }
+}

src/HelloShop.ServiceDefaults/DistributedLocks/IDistributedLockResult.cs

@@ -0,0 +1,13 @@
+// Copyright (c) HelloShop Corporation. All rights reserved.
+// See the license file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace HelloShop.ServiceDefaults.DistributedLocks
+{
+    public interface IDistributedLockResult : IAsyncDisposable { }
+}