TrustGate provides comprehensive monitoring capabilities through a Prometheus metrics endpoint. This guide explains how to access and interpret these metrics to monitor your gateway’s performance and health.

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Configuration

Metrics collection can be configured in your TrustGate configuration file:

server:
  admin_port: 8080
  metrics_port: 9090  # Port where metrics are exposed
  proxy_port: 8081
  base_domain: example.com

metrics:
  enabled: true               # Enable/disable all metrics
  enable_latency: true       # Basic latency metrics
  enable_upstream: true      # Upstream latency (high cardinality)
  enable_connections: true   # Connection tracking
  enable_per_route: true    # Per-route metrics (high cardinality)
  enable_detailed_status: true # Detailed status codes

TrustGate exposes metrics at the /metrics endpoint in Prometheus format. These metrics provide insights into request processing, latency, connections, and overall system health.

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Connection Metrics

# HELP trustgate_connections Number of active connections
# TYPE trustgate_connections gauge

This gauge metric tracks the number of active connections to your gateway. It includes the following labels:

  • gateway_id: Unique identifier for the gateway instance
  • state: Connection state (e.g., “active”)

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Request Metrics

# HELP trustgate_requests_total Total number of requests processed
# TYPE trustgate_requests_total counter

This counter tracks the total number of requests processed by the gateway with labels for:

  • gateway_id: Gateway instance identifier
  • method: HTTP method (GET, POST, etc.)
  • status: HTTP status code category (2xx, 4xx, 5xx)

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Latency Metrics

TrustGate provides three types of latency histograms:

  1. Overall Request Latency
# HELP trustgate_latency_ms Request latency in milliseconds
# TYPE trustgate_latency_ms histogram
  1. Detailed Route/Service Latency
# HELP trustgate_detailed_latency_ms Detailed request latency by service and route
# TYPE trustgate_detailed_latency_ms histogram
  1. Upstream Service Latency
# HELP trustgate_upstream_latency_ms Upstream service latency in milliseconds
# TYPE trustgate_upstream_latency_ms histogram

All latency metrics include bucket ranges from 5ms to 30s and provide:

  • gateway_id: Gateway instance identifier
  • route: Route ID (for detailed and upstream metrics)
  • service: Service ID (for detailed and upstream metrics)
  • type: Request path (for overall latency)

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Prometheus Handler Metrics

# HELP promhttp_metric_handler_requests_in_flight Current number of scrapes being served
# TYPE promhttp_metric_handler_requests_in_flight gauge

# HELP promhttp_metric_handler_requests_total Total number of scrapes by HTTP status code
# TYPE promhttp_metric_handler_requests_total counter

These metrics provide information about the Prometheus metrics endpoint itself.