Metrics Exporters

Fasq provides a flexible metrics export system that allows you to send performance data to external monitoring systems, log files, or analytics platforms in a Riverpod-idiomatic way.

Configuration

[!TIP] We are developing the fasq_metrics package to provide turn-key metrics exporting for Riverpod-based applications, including automated OpenTelemetry integration.

In Fasq Riverpod, you configure metrics exporters by overriding the fasqMetricsConfigProvider. This provider provides a MetricsConfig object that specifies the exporters to use, the export interval, and whether auto-export is enabled.

Available Exporters

The core fasq package provides several built-in exporters:

ConsoleExporter: Outputs metrics to the console. Great for development.
JsonExporter: Exports metrics as JSON strings.
OpenTelemetryExporter: Sends metrics to OpenTelemetry-compatible backends (OTLP).

Setup Example

To enable metrics export, override fasqMetricsConfigProvider in your ProviderScope:


import 'package:fasq/fasq.dart';
import 'package:fasq_riverpod/fasq_riverpod.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
 
void main() {
  runApp(
    ProviderScope(
      overrides: [
        fasqMetricsConfigProvider.overrideWithValue(
          MetricsConfig(
            exporters: [
              // Export to console for development
              ConsoleExporter(),
 
              // Export to an OTLP collector for production
              OpenTelemetryExporter(
                endpoint: 'https://otel.example.com/v1/metrics',
              ),
            ],
            enableAutoExport: true,
            exportInterval: const Duration(minutes: 1),
          ),
        ),
      ],
      child: MyApp(),
    ),
  );
}

Automatic Export

When enableAutoExport is set to true, the QueryClient will automatically trigger an export of gathered performance metrics at the specified exportInterval.

This is handled internally by the QueryClient and requires no additional setup when using fasq_riverpod.

Manual Export

If you prefer to trigger exports manually, you can access the QueryClient and call exportMetricsManually():


final client = ref.read(fasqClientProvider);
await client.exportMetricsManually();

Custom Exporters

You can create custom exporters by implementing the MetricsExporter interface from the core fasq package and including them in your MetricsConfig.


class MyCustomExporter implements MetricsExporter {
  @override
  Future<void> export(PerformanceSnapshot snapshot) async {
    // Custom export logic here...
  }
 
  @override
  void configure(Map<String, dynamic> config) {
    // Optional configuration logic...
  }
}

Best Practices

Interval Balancing: Set an exportInterval that balances the need for fresh data with the overhead of network requests.
Environment Specifics: Use different exporters for different environments (e.g., ConsoleExporter for dev, OpenTelemetryExporter for prod).
Error Handling: Fasq’s export system is fault-tolerant; a failure in one exporter will not affect others.