add MaxConcurrentConnections

src/Hotline.Api/Program.cs

@@ -11,6 +11,12 @@ try
 
     var builder = WebApplication.CreateBuilder(args);
 
+    builder.WebHost.ConfigureKestrel(serverOptions =>
+    {
+        serverOptions.Limits.MaxConcurrentConnections = 2000;
+        serverOptions.Limits.MaxConcurrentUpgradedConnections = 2000;
+    });
+
     builder.Host
         .ConfigureAppConfiguration((hostBuilderContext, configBuilder) =>
         {