Network Best Practices - Microsoft Docs

Network Best Practices for .NET Applications

This document outlines essential network best practices for developing and deploying robust, performant, and secure .NET applications. Following these guidelines can significantly improve your application's reliability and user experience.

1. Minimize Network Hops and Latency

Every network hop adds latency. Design your architecture to reduce the number of intermediaries between clients and servers, and between different services within your application.

Service Colocation: Deploy services that frequently communicate with each other in the same datacenter or region.
Client-Side Caching: Cache frequently accessed data on the client to reduce repeated requests.
Content Delivery Networks (CDNs): Utilize CDNs for static assets to serve content from locations geographically closer to users.

2. Optimize Data Transfer

The amount of data transferred directly impacts performance and cost. Reduce payload sizes and transfer only necessary information.

Compression: Enable HTTP compression (e.g., Gzip, Brotli) for text-based payloads like JSON and HTML.
Data Serialization: Choose efficient serialization formats. JSON is widely used, but binary formats like Protocol Buffers or MessagePack can be more performant for internal service-to-service communication.
Batching: Combine multiple small requests into a single larger request where appropriate, especially for operations that can be batched.
Selective Data Fetching: Avoid over-fetching data. Use APIs that allow clients to specify exactly which fields they need.

3. Implement Robust Error Handling and Retries

Network operations are inherently unreliable. Your application must gracefully handle transient failures.

Idempotent Operations: Design APIs so that making the same request multiple times has the same effect as making it once. This is crucial for safe retries.
Exponential Backoff: When retrying failed requests, implement an exponential backoff strategy with jitter to avoid overwhelming the server and to allow recovery.
Circuit Breakers: Implement circuit breaker patterns to prevent cascading failures. If a service repeatedly fails, the circuit breaker can stop sending requests to it for a period.

Tip: Use the Polly library in .NET for easily implementing resilience policies like retries, circuit breakers, and timeouts.

4. Secure Network Communications

Protect data in transit from eavesdropping and tampering.

HTTPS Everywhere: Always use TLS/SSL (HTTPS) for all communication, including internal service-to-service calls.
Strong TLS Configuration: Configure your TLS with modern cipher suites and protocols.
Network Segmentation: Isolate critical services and data using network firewalls and virtual private clouds (VPCs).
Authentication and Authorization: Secure your APIs with robust authentication and authorization mechanisms.

5. Monitor Network Performance

Visibility into network behavior is key to identifying and resolving issues.

Latency Tracking: Monitor request latency between services and from clients to your application.
Error Rates: Track the frequency of network-related errors (e.g., timeouts, connection errors).
Throughput: Monitor the amount of data being transferred.

By adhering to these network best practices, you can build more resilient, efficient, and secure .NET applications that deliver an exceptional user experience.

Example: Using HttpClient with a Timeout

Here's a C# example demonstrating how to configure a timeout for an `HttpClient`:


using System;
using System.Net.Http;
using System.Threading.Tasks;

public class NetworkClient
{
    private static readonly HttpClient client = new HttpClient
    {
        // Set a default timeout for all requests made by this HttpClient instance
        Timeout = TimeSpan.FromSeconds(30)
    };

    public async Task<string> GetDataAsync(string url)
    {
        try
        {
            HttpResponseMessage response = await client.GetAsync(url);
            response.EnsureSuccessStatusCode(); // Throws an exception if the status code is not success
            return await response.Content.ReadAsStringAsync();
        }
        catch (TaskCanceledException ex)
        {
            // This exception is often thrown when the request times out
            Console.WriteLine($"Request timed out: {ex.Message}");
            throw; // Re-throw or handle as needed
        }
        catch (HttpRequestException ex)
        {
            Console.WriteLine($"HTTP request error: {ex.Message}");
            throw;
        }
    }

    // It's good practice to dispose of HttpClient when you're done,
    // or use IHttpClientFactory for better management.
    // For a long-lived application, a single HttpClient instance is generally recommended.
}