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
8public 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(
36                "corn",
37                100 + Random.Shared.Next( 20 ),
38                $"Updated by {this._appName}, i={i}" );
39
40            Console.WriteLine( $"{this._appName} update {updatedCorn}." );
41            this._productCatalogue.Update( updatedCorn );
42        }
43
44        Console.WriteLine(
45            $"In total, CloudCalculator in {this._appName} performed {this._productCatalogue.DbOperationCount} database operation(s)." );
46    }
47}

Getting the product of corn from database.
Getting the product of corn from database.
App2 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App1 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. }.
App2 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App1 reads and gets Product { Id = corn, Price = 100, Remarks = Initial record. }.
App1 update Product { Id = corn, Price = 111, Remarks = Updated by App1, i=0 }.
App2 update Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
Updating the product corn.
Updating the product corn.
Getting the product of corn from database.
Getting the product of corn from database.
App1 reads and gets Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
App2 reads and gets Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
App1 reads and gets Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
App2 reads and gets Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
App1 reads and gets Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
App2 reads and gets Product { Id = corn, Price = 110, Remarks = Updated by App2, i=0 }.
App2 update Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App1 update Product { Id = corn, Price = 104, Remarks = Updated by App1, i=1 }.
Updating the product corn.
Updating the product corn.
Getting the product of corn from database.
Getting the product of corn from database.
App1 reads and gets Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App2 reads and gets Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App1 reads and gets Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App2 reads and gets Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App1 reads and gets Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App2 reads and gets Product { Id = corn, Price = 107, Remarks = Updated by App2, i=1 }.
App1 update Product { Id = corn, Price = 111, Remarks = Updated by App1, i=2 }.
Updating the product corn.
App2 update Product { Id = corn, Price = 105, Remarks = Updated by App2, i=2 }.
Updating the product corn.
In total, CloudCalculator in App2 performed 6 database operation(s).
In total, CloudCalculator in App1 performed 6 database operation(s).

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
11internal 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        // 
30        // Add the caching service.
31        builder.Services.AddMetalamaCaching(
32            caching =>
33                caching.WithBackend(
34                    backend =>
35                        backend.Memory()
36                            .WithAzureSynchronization(
37                                connectionString ) ) );
38        // 
39
40        // Add other components as usual.
41        builder.Services.AddAsyncConsoleMain<ConsoleMain>();
42        builder.Services.AddSingleton<ProductCatalogue>();
43
44        // Build the application.
45        await using var app = builder.Build( [name] );
46
47        // 
48        await app.Services.GetRequiredService<ICachingService>().InitializeAsync();
49        // 
50
51        // Run the application.
52        await app.RunAsync();
53    }
54}