Synchronizing local in-memory caches for multiple servers

1using System;
2using Metalama.Documentation.Helpers.ConsoleApp;
3using System.Threading;
4using System.Threading.Tasks;
5
6namespace Doc.AzureSynchronized
7{
8    public sealed class ConsoleMain : IAsyncConsoleMain
9    {
10        private readonly ProductCatalogue _productCatalogue;
11        private readonly string _appName;
12
13        public ConsoleMain( ProductCatalogue productCatalogue, IConsoleHost host )
14        {
15            this._productCatalogue = productCatalogue;
16            this._appName = host.Arguments[0];
17        }
18
19        public async Task ExecuteAsync()
20        {
21            // Force running in parallel.
22            await Task.Yield();
23
24            for ( var i = 0; i < 3; i++ )
25            {
26                for ( var j = 0; j < 3; j++ )
27                {
28                    // Getting the product.
29                    var corn = this._productCatalogue.GetProduct( "corn" );
30                    Console.WriteLine( $"{this._appName} reads and gets {corn}." );
31                    await Task.Delay( 20 + Random.Shared.Next( 4 ) );
32                }
33
34                // Updating the product.
35                var updatedCorn = new Product( "corn", 100 + Random.Shared.Next( 20 ), $"Updated by {this._appName}, i={i}" );
36                Console.WriteLine( $"{this._appName} update {updatedCorn}." );
37                this._productCatalogue.Update( updatedCorn );
38            }
39
40            Console.WriteLine( $"In total, CloudCalculator in {this._appName} performed {this._productCatalogue.DbOperationCount} database operation(s)." );
41        }
42    }
43}

1using Metalama.Documentation.Helpers.ConsoleApp;
2using Metalama.Documentation.Helpers.Security;
3using Metalama.Patterns.Caching;
4using Metalama.Patterns.Caching.Backends.Azure;
5using Metalama.Patterns.Caching.Building;
6using Microsoft.Extensions.DependencyInjection;
7using System.Threading.Tasks;
8
9namespace Doc.AzureSynchronized
10{
11    internal static class Program
12    {
13        public static async Task Main()
14        {
15            // We simulate two applications running in parallel.
16            var app1 = RunApp( "App1" );
17            var app2 = RunApp( "App2" );
18
19            await Task.WhenAll( app1, app2 );
20        }
21
22        private static async Task RunApp( string name )
23        {
24            var builder = ConsoleApp.CreateBuilder();
25
26            // Get the connection string.
27            var connectionString = Secrets.Get( "CacheInvalidationTestServiceBusConnectionString" );
28
29            // Add the caching service.
30            builder.Services.AddMetalamaCaching(
31                caching =>
32                    caching.WithBackend(
33                        backend =>
34                            backend.Memory().WithAzureSynchronization( connectionString ) ) );
35
36            // Add other components as usual.
37            builder.Services.AddAsyncConsoleMain<ConsoleMain>();
38            builder.Services.AddSingleton<ProductCatalogue>();
39
40            // Build the application.
41            await using var app = builder.Build( new[] { name } );
42
43            await app.Services.GetRequiredService<ICachingService>().InitializeAsync();
44
45
46            // Run the application.
47            await app.RunAsync();
48        }
49    }
50}

Getting the product of corn from database.
App2 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
Getting the product of corn from database.
App1 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App2 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App1 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App2 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App1 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App2 update Product { Id = corn, Price = 102, Remarks = Updated by App2, i=0 }.
Updating the product corn.
Getting the product of corn from database.
App2 reads and gets Product { Id = corn, Price = 102, Remarks = Updated by App2, i=0 }.
App1 update Product { Id = corn, Price = 105, Remarks = Updated by App1, i=0 }.
Updating the product corn.
Getting the product of corn from database.
App1 reads and gets Product { Id = corn, Price = 105, Remarks = Updated by App1, i=0 }.
App2 reads and gets Product { Id = corn, Price = 102, Remarks = Updated by App2, i=0 }.
App1 reads and gets Product { Id = corn, Price = 105, Remarks = Updated by App1, i=0 }.
App2 reads and gets Product { Id = corn, Price = 102, Remarks = Updated by App2, i=0 }.
App1 reads and gets Product { Id = corn, Price = 105, Remarks = Updated by App1, i=0 }.
App2 update Product { Id = corn, Price = 116, Remarks = Updated by App2, i=1 }.
Updating the product corn.
Getting the product of corn from database.
App2 reads and gets Product { Id = corn, Price = 116, Remarks = Updated by App2, i=1 }.
App1 update Product { Id = corn, Price = 103, Remarks = Updated by App1, i=1 }.
Updating the product corn.
Getting the product of corn from database.
App1 reads and gets Product { Id = corn, Price = 103, Remarks = Updated by App1, i=1 }.
App2 reads and gets Product { Id = corn, Price = 116, Remarks = Updated by App2, i=1 }.
App1 reads and gets Product { Id = corn, Price = 103, Remarks = Updated by App1, i=1 }.
App2 reads and gets Product { Id = corn, Price = 116, Remarks = Updated by App2, i=1 }.
App1 reads and gets Product { Id = corn, Price = 103, Remarks = Updated by App1, i=1 }.
App2 update Product { Id = corn, Price = 106, Remarks = Updated by App2, i=2 }.
Updating the product corn.
In total, CloudCalculator in App2 performed 6 database operation(s).
App1 update Product { Id = corn, Price = 113, Remarks = Updated by App1, i=2 }.
Updating the product corn.
In total, CloudCalculator in App1 performed 6 database operation(s).