Advanced Features

Enhance your logging with PII masking, correlation IDs, enrichers, and sampling.

---

PII Masking

Automatically mask sensitive data in your logs:

{
  "PrimusLogging": {
    "ApplicationId": "MyService",
    "Targets": [
      { "Type": "console", "Pretty": true }
    ],
    "Pii": {
      "MaskEmails": true,
      "MaskCreditCards": true,
      "MaskSSN": true,
      "MaskPasswords": true,
      "MaskTokens": true,
      "MaskSecrets": true
    }
  }
}

Result:

Original	Masked
user@example.com	u***@***.com
4111111111111111	************1111
123-45-6789	***-**-****

Custom PII Patterns

Mask custom sensitive data:

{
  "Pii": {
    "MaskEmails": true,
    "CustomSensitiveKeys": ["apiKey", "secret"],
    "CustomRegexPatterns": ["ORD-\\d{8}"]
  }
}

---

Correlation IDs

The UsePrimusLogging() middleware automatically:

• Generates a unique X-Correlation-ID for each request
• Adds the correlation ID to all log entries
• Returns the header in responses for tracing

var app = builder.Build();
app.UsePrimusLogging();  // Enables correlation IDs

---

Custom Enrichers

Add context to every log entry. Built-in enrichers: PropertyEnricher, MachineNameEnricher, ThreadIdEnricher.

// At the top of Program.cs — you need BOTH usings
using PrimusSaaS.Logging.Core;       // for enricher classes
using PrimusSaaS.Logging.Extensions; // for AddPrimus()

builder.Logging.AddPrimus(opts =>
{
    builder.Configuration.GetSection("PrimusLogging").Bind(opts);

    // Static properties
    opts.Enrichers.Add(new PropertyEnricher("Application", "OrderService"));
    opts.Enrichers.Add(new PropertyEnricher("Environment", builder.Environment.EnvironmentName));

    // Machine/thread info
    opts.Enrichers.Add(new MachineNameEnricher());
    opts.Enrichers.Add(new ThreadIdEnricher());
});

All three enricher classes live in the PrimusSaaS.Logging.Core namespace. Without this using, the compiler will not find them.

---

Sampling

Reduce log volume in high-traffic scenarios.

Option A — via appsettings.json (recommended):

{
  "PrimusLogging": {
    "Sampling": {
      "Enabled": true,
      "SampleRate": 0.10,
      "AlwaysLogOnError": true
    }
  }
}

Option B — via code:

builder.Logging.AddPrimus(opts =>
{
    builder.Configuration.GetSection("PrimusLogging").Bind(opts);
    opts.SamplingRate = 0.10;      // Keep 10% of low-importance logs
    opts.AlwaysLogOnError = true;  // Never sample out errors
});

is a convenience shortcut — setting it to automatically enables sampling with a 10% rate. ensures errors are never dropped.

---

Multiple Targets

Send logs to multiple destinations:

{
  "PrimusLogging": {
    "ApplicationId": "MyService",
    "Environment": "Production",
    "MinLevel": 1,
    "Targets": [
      { "Type": "console", "Pretty": true },
      { "Type": "file", "Path": "logs/app.log" },
      { "Type": "applicationInsights", "ConnectionString": "..." }
    ],
    "Pii": {
      "MaskEmails": true,
      "MaskCreditCards": true
    }
  }
}

---

Category Truncation

Shorten long category names:

builder.Logging.AddPrimus(opts =>
{
    builder.Configuration.GetSection("PrimusLogging").Bind(opts);
    opts.TruncateCategoryNames = true;
    opts.MaxCategoryLength = 40;  // Default: 120
});

---

Structured Logging Tips

1. Use message templates with named properties:

   _logger.LogInformation("Order {OrderId} placed by {UserId}", orderId, userId);

2. Use scopes for request-specific context:

   using (_logger.BeginScope(new Dictionary<string, object> { { "OrderId", order.Id } }))
   {
       _logger.LogInformation("Processing order");
   }

3. Pass exceptions as the first parameter:

   _logger.LogError(ex, "Payment failed for {OrderId}", order.Id);