MSDN Documentation

Optimizing ASP.NET Core Application Performance

This section provides comprehensive guidance and best practices for enhancing the performance of your ASP.NET Core applications. Achieving high performance is crucial for delivering a responsive user experience, reducing infrastructure costs, and ensuring scalability.

Key Areas for Performance Optimization

1. Request Processing Pipeline

Understand how ASP.NET Core processes requests and identify bottlenecks:

• Middleware Order: The order of middleware significantly impacts performance. Place frequently used middleware earlier in the pipeline.
• Endpoint Routing: Efficient routing configuration can reduce overhead.
• Action Filters: Use filters judiciously; complex filters can add latency.

2. Data Access and Caching

Optimize how your application interacts with data sources:

• Database Queries: Write efficient SQL queries. Use ORM features like query caching and lazy loading appropriately.
• Caching Strategies:
  • In-Memory Caching: For frequently accessed, relatively static data.
  • Distributed Caching: Using Redis or Memcached for shared caching across multiple instances.
  • HTTP Caching: Leverage response caching middleware.
• Connection Pooling: Ensure database connections are efficiently managed.

3. Response Generation and Serialization

Minimize the overhead associated with sending data back to the client:

• JSON Serialization: Use System.Text.Json for better performance compared to Newtonsoft.Json. Configure it for optimal speed.
• Response Compression: Enable response compression middleware to reduce bandwidth usage.
• Payload Size: Avoid sending unnecessary data. Consider techniques like GraphQL or selective field retrieval.

4. Asynchronous Programming

Embrace asynchronous patterns to avoid blocking threads:

• async and await: Use them consistently for I/O-bound operations.
• Task-based APIs: Prefer Task-based APIs over older Begin/End patterns.

5. Hosting and Deployment

Server configuration and deployment strategy are critical:

• Kestrel: ASP.NET Core's built-in web server is highly performant. Tune its configuration.
• Reverse Proxies: Use Nginx or IIS as reverse proxies for SSL termination, load balancing, and static file serving.
• Environment Variables: Configure settings using environment variables for flexibility.
• Containerization: Optimize Docker images for size and startup time.

6. Profiling and Monitoring Tools

Essential tools for diagnosing performance issues:

• Visual Studio Profiler: For in-depth CPU and memory analysis.
• Application Insights: For real-time monitoring, performance counters, and exception tracking.
• dotnet-trace and dotnet-counters: Command-line tools for performance tracing and metrics.

Code Examples

Enabling Response Compression

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddResponseCompression();

var app = builder.Build();

// Configure the HTTP request pipeline.
app.UseResponseCompression();

// ... other middleware
            

Using System.Text.Json for Serialization

using System.Text.Json;

public class MyData
{
    public int Id { get; set; }
    public string Name { get; set; }
}

// ...

var data = new MyData { Id = 1, Name = "Example" };
var jsonString = JsonSerializer.Serialize(data); // High-performance JSON serialization
            

Basic In-Memory Caching

using Microsoft.Extensions.Caching.Memory;

// In Startup.cs or Program.cs
// builder.Services.AddMemoryCache();

// In your service or controller
private readonly IMemoryCache _cache;

public MyService(IMemoryCache cache)
{
    _cache = cache;
}

public string GetData(int id)
{
    string cacheKey = $"myData_{id}";
    if (_cache.TryGetValue(cacheKey, out string cachedData))
    {
        return cachedData;
    }

    // Simulate fetching data
    string data = FetchDataFromSource(id);

    var cacheEntryOptions = new MemoryCacheEntryOptions()
        .SetSlidingExpiration(TimeSpan.FromMinutes(5)); // Example expiration

    _cache.Set(cacheKey, data, cacheEntryOptions);
    return data;
}

private string FetchDataFromSource(int id)
{
    // Your actual data fetching logic here
    return $"Data for item {id}";
}
            

Further Reading

• ASP.NET Core Performance: Autodetect and tune
• ASP.NET Core Response Compression
• ASP.NET Core Startup Performance