cold start optimization

Program.cs

@@ -12,42 +12,15 @@
     .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
     .AddUserSecrets<EnvironmentSpecificSettings>(optional: true)
     .AddEnvironmentVariables();
-
-// Add services to the container.
-
 builder.Services.AddSignalR();
-//builder.Services.AddCors();
-//builder.Services.AddControllers();
-//// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
-//builder.Services.AddEndpointsApiExplorer();
-//builder.Services.AddSwaggerGen();
-
-builder.Services.Add(ServiceDescriptor.Singleton<IMemoryCache, MemoryCache>());
+builder.Services.AddMemoryCache();
 builder.Services.AddSingleton<GroupService>();
 
 var app = builder.Build();
 
-// Configure the HTTP request pipeline.
-//if (app.Environment.IsDevelopment())
-//{
-//    app.UseSwagger();
-//    app.UseSwaggerUI();
-//}
-
-//app.UseHttpsRedirection();
-
-//app.UseAuthorization();
-
-//app.MapControllers();
-
-//app.Run();
-
-//app.UseCors(builder =>
-//{
-//    builder.WithOrigins(origins: environmentSettings.AllowedCorsOrigins ?? []);
-//    builder.AllowAnyHeader();
-//    builder.AllowAnyMethod();
-//});
+// Preload SignalR hubs by making a dummy connection during startup
+var hubContext = app.Services.GetService<IHubContext<BeepHub>>();
+await hubContext.Clients.All.SendAsync("preload");
 
 app.UseHttpsRedirection();
 app.UseRouting();
@@ -59,11 +32,10 @@
     (HttpContext context, GroupService groupService) =>
         groupService.GetConnectionsByGroup(context.Request.Query["groupName"])
 );
-
+app.MapGet("/healthcheck", () => "1");
 
 app.Run();
 
-
 public class BeepHub : Hub
 {
     private readonly GroupService _groupService;
@@ -73,7 +45,6 @@ public BeepHub(GroupService groupService)
         _groupService = groupService;
     }
 
-
     public async Task Play(string freqInKhz, string durationInSeconds, string groupName)
     {
         Console.WriteLine("Play -  freqInKhz=" + freqInKhz + ", durationInSeconds:" + durationInSeconds + ", group:" + groupName);

remote-beep-backend.csproj

@@ -7,6 +7,12 @@
     <RootNamespace></RootNamespace>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <PublishTrimmed>true</PublishTrimmed>
+    <PublishReadyToRun>true</PublishReadyToRun>
+    <TieredCompilation>true</TieredCompilation>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
   </ItemGroup>