Tags

// Add multiple tags
Log.WithTags("performance", "database")
   .Info("Database query completed");

// Single tag
Log.WithTags("authentication")
   .Warn("Failed login attempt");

// Tags for different categories
Log.WithTags("cache", "performance")
   .Debug("Cache hit for product data");
   
Log.WithTags("api", "external")
   .Error("External API call failed");

// Authentication feature
Log.WithTags("authentication", "security")
   .Info("Login attempt successful");

// Payment processing
Log.WithTags("payment", "transaction")
   .Error("Payment gateway timeout");

// Database operations
Log.WithTags("database", "orders")
   .Warn("Slow query detected");

// Business critical operations
Log.WithTags("critical", "infrastructure")
   .Error("Database connection lost");

// Performance issues
Log.WithTags("performance", "database")
   .Warn("Query execution time exceeded threshold");

// Security events
Log.WithTags("security", "authentication")
   .Warn("Multiple failed login attempts detected");

// Cache operations
Log.WithTags("cache", "redis")
   .Info("Cache entry expired");

// External APIs
Log.WithTags("api", "external", "payment-gateway")
   .Error("External service unavailable");

// Background jobs
Log.WithTags("background-job", "email")
   .Info("Email processing completed");

// ✅ Good - Lowercase with hyphens
Log.WithTags("user-management", "profile")
   .Info("Profile updated successfully");

// ✅ Good - Simple and clear
Log.WithTags("database", "performance")
   .Warn("Slow query detected");

// ❌ Avoid - Inconsistent casing and spaces
Log.WithTags("UserManagement", "PROFILE")
   .Info("Profile updated");
   
Log.WithTags("database performance", "slow query")
   .Warn("Query too slow");

// Component tags
Log.WithTags("database", "redis", "cache")
   .Info("Cache operation completed");

// Feature tags
Log.WithTags("authentication", "security", "login")
   .Error("Authentication failed");

// Environment/severity tags
Log.WithTags("critical", "infrastructure", "production")
   .Error("System overload detected");

// All payment-related logs can be filtered by "payment" tag
Log.WithTags("payment", "gateway")
   .Info("Payment processing started");
   
Log.WithTags("payment", "retry")
   .Warn("Payment retry attempt");
   
Log.WithTags("payment", "error")
   .Error("Payment processing failed");

// Filter by multiple criteria
Log.WithTags("database", "performance", "critical")
   .Error("Database connection pool exhausted");

// Specific component tracking
Log.WithTags("cache", "redis", "performance")
   .Warn("Cache response time exceeded threshold");

[ApiController]
[Route("api/[controller]")]
public class OrdersController : ControllerBase
{
    [HttpPost]
    public async Task<IActionResult> CreateOrder(OrderRequest request)
    {
        Log.WithTags("api", "orders", "create")
           .Info("Order creation started");
        
        try
        {
            var order = await _orderService.CreateOrderAsync(request);
            
            Log.WithTags("api", "orders", "success")
               .Info("Order created successfully");
               
            return Ok(order);
        }
        catch (Exception ex)
        {
            Log.WithTags("api", "orders", "error")
               .Error("Order creation failed");
            return StatusCode(500);
        }
    }
}

public class RequestLoggingMiddleware
{
    private readonly RequestDelegate _next;

    public RequestLoggingMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        var moduleTag = GetModuleTag(context.Request.Path);
        
        Log.WithTags("http", "request", moduleTag)
           .Info("HTTP request started");
        
        try
        {
            await _next(context);
            
            Log.WithTags("http", "request", moduleTag, "completed")
               .Info("HTTP request completed");
        }
        catch (Exception ex)
        {
            Log.WithTags("http", "request", moduleTag, "error")
               .Error("HTTP request failed");
            throw;
        }
    }
    
    private string GetModuleTag(string path)
    {
        return path switch
        {
            var p when p.StartsWith("/api/orders") => "orders",
            var p when p.StartsWith("/api/products") => "products",
            var p when p.StartsWith("/api/payments") => "payments",
            _ => "general"
        };
    }
}