.NET Core 2迁移后Web应用初始加载及登出缓慢问题求助

Hey there, let's work through this slow initial load and logout issue you're hitting with your .NET Core 2 app. I've troubleshooted similar performance bottlenecks before, so here are some targeted steps to diagnose and fix this:

1. Optimize .cshtml View Rendering #

Since you suspect view rendering is the culprit, let's tackle that first:

• Enable View Precompilation: By default, .NET Core 2 might compile views on the first request, which adds significant latency. Add these settings to your .csproj file to precompile views during build/publish:

  <PropertyGroup>
    <MvcRazorCompileOnPublish>true</MvcRazorCompileOnPublish>
    <RazorCompileOnBuild>true</RazorCompileOnBuild>
  </PropertyGroup>
  

  This eliminates the runtime compilation hit on initial load.
• Trim View Logic: Check your .cshtml files (especially layout pages and logout views) for heavy operations like database queries, complex loops, or external service calls. Move all business logic to controllers or service classes—views should only handle rendering.
• Optimize Layout Resources: If your layout page loads multiple CSS/JS files, combine and minify them to reduce HTTP requests. Avoid render-blocking resources where possible (e.g., defer non-critical JS).

2. Fix HTTPS Performance Without Ditching It #

Since HTTPS is mandatory, let's optimize how Kestrel handles SSL:

• Cache Your SSL Certificate: If you're loading the certificate from disk on every request, that's a big overhead. Load it once at startup and reuse it:

  var cert = new X509Certificate2("path/to/your/cert.pfx", "your-cert-password");
  
  WebHost.CreateDefaultBuilder(args)
      .UseKestrel(options =>
      {
          options.ListenAnyIP(443, listenOptions =>
          {
              listenOptions.UseHttps(cert);
          });
      })
      .UseStartup<Startup>();
  

• Tune TLS Settings: Disable outdated TLS protocols to speed up handshake times. Stick to TLS 1.2 or newer:

  options.ListenAnyIP(443, listenOptions =>
  {
      listenOptions.UseHttps(cert);
      listenOptions.Protocols = HttpProtocols.Http1AndHttp2;
      listenOptions.SslProtocols = SslProtocols.Tls12 | SslProtocols.Tls13;
  });
  

• Verify Certificate Trust: If using a self-signed certificate in non-production, ensure it's added to the server's trusted root store. Unverified certificates can cause extra validation delays.

3. Optimize Application Insights (If You Re-enable It) #

You saw a speed boost when removing AI, but you can tweak it to minimize overhead:

• Adjust Sampling Rate: Reduce the volume of telemetry data collected to cut down on processing. Add this to your appsettings.json:

  "ApplicationInsights": {
      "InstrumentationKey": "your-key",
      "Sampling": {
          "Enabled": true,
          "Percentage": 10.0
      }
  }
  

• Disable Unneeded Telemetry: Turn off modules you don't use (e.g., performance counters, dependency tracking for internal services) via the TelemetryConfiguration in your Startup class.

4. Dig Deeper with Diagnostics #

• Enable Detailed Logging: Add timestamped logs to track exactly where time is being spent during initial load and logout. Use ILogger to log each step (e.g., "Controller action started", "View rendering started") and compare timestamps.
• Check Session Management: Logout often involves cleaning up session data. If you're using in-memory session storage, ensure you're not storing excessive data. For multi-server setups, switch to a distributed cache like Redis for faster session operations.
• Monitor Server Resources: Check CPU, memory, and disk IO during slow operations. High disk IO could indicate slow view file or certificate reads; high CPU might point to inefficient code in views or services.

Give these steps a try—start with view precompilation and certificate caching, as those are quick wins that often resolve these exact issues. Let me know if you hit any roadblocks!

内容的提问来源于stack exchange，提问作者user6728767