CK.Monitoring.Metrics

CK.Monitoring.Metrics

Integrates CK.Metrics with CK.Monitoring by providing a GrandOutputHandler that writes metrics to a high-performance FasterLog.

Important: This package does not work on its own. The MetricsLogHandler requires a FasterLog instance to be injected at runtime. Use CK.AppIdentity.Monitoring.Metrics which provides MetricsFeatureDriver that manages the FasterLog lifecycle and injects it into the handler automatically.

Overview

This package provides:

• MetricsLogHandler: A sealed IGrandOutputHandler that receives metrics from the GrandOutput pipeline and writes them to FasterLog
• MetricsLogDispatcher: A parser for metrics log entries that dispatches to typed callbacks

The handler acts as a producer only - it writes metrics entries to FasterLog but does not consume them. Consumers are implemented separately (see CK.AppIdentity.Monitoring.Metrics).

Configuration

Add the handler to GrandOutput configuration:

{
  "CK-Monitoring": {
    "GrandOutput": {
      "Handlers": {
        "MetricsLogHandler, CK.Monitoring.Metrics": {
          "CommitRate": 1
        }
      }
    }
  }
}

Or simply enable with defaults:

{
  "CK-Monitoring": {
    "GrandOutput": {
      "Handlers": {
        "MetricsLogHandler, CK.Monitoring.Metrics": true
      }
    }
  }
}

Configuration Options

Property	Type	Default	Description
CommitRate	int	1	Multiplier of GrandOutput.TimerDuration (default 500ms) between FasterLog commits. A value of 1 commits every 500ms, 2 every 1 second, etc.

How It Works

1. The handler receives log entries tagged with DotNetMetrics.MetricsTag from the GrandOutput pipeline
2. Each entry is written to FasterLog with a timestamp prefix (8 bytes DateTime binary + ASCII text)
3. FasterLog provides durability and supports multiple named consumers via persisted iterators

FasterLog Injection

The handler does not create or own the FasterLog instance. Instead, the FasterLog must be injected at runtime by calling MetricsLogHandler.SetFasterLog(FasterLog). Without this injection, the handler silently ignores all metrics entries.

Recommended approach: Use CK.AppIdentity.Monitoring.Metrics which provides MetricsFeatureDriver. This feature driver:

1. Creates and manages the FasterLog instance
2. Automatically injects it into the handler via SetMetricsFasterLogAction (a GrandOutputHandlersAction)
3. Handles consumer registration and log truncation
4. Cleans up orphaned consumers on shutdown

This design allows:

• The handler to be configured via standard GrandOutput configuration
• The FasterLog lifecycle to be managed externally (by AppIdentity or custom code)
• Multiple consumers to share the same FasterLog instance

Entry Format

Each FasterLog entry contains:

• 8 bytes: DateTime as binary (via DateTime.ToBinary())
• Remaining bytes: ASCII-encoded metrics text

The text format follows the CK.Metrics log format for meters, instruments, and measurements.

Related Packages

• CK.Metrics - Core metrics collection
• CK.AppIdentity.Monitoring.Metrics - AppIdentity integration with consumer support
• CK.AppIdentity.Monitoring.Metrics.Csv - CSV export consumer