gRPC Health Monitor

The gRPC monitor in updu calls the standard grpc.health.v1.Health/Check RPC against your service and considers the monitor Up only when the response status is SERVING. This is the same probe used by Kubernetes' gRPC liveness checks and Istio service health, so any server that already exposes the standard health protocol works without changes.

Configuration Options

When setting up a gRPC monitor, you can configure the following options:

Basic Settings

• Name: A descriptive name for your monitor.
• Group: Optional group assignment for organizing monitors.
• Interval (seconds): How frequently updu should perform the check.
• Timeout (seconds): Maximum time updu waits for the gRPC client to dial and complete the health RPC.

gRPC Specific Settings

• Hostname: The IP address or domain name of the gRPC server (e.g., payments.internal.example).
• Port: The TCP port the gRPC server listens on (commonly 50051).
• Service: (Optional) The fully-qualified service name passed in the HealthCheckRequest (e.g., payments.v1.PaymentService). Leave empty to query overall server health.
• TLS: Enable when the server requires a TLS transport. updu uses TLS 1.2 or higher.
• Skip TLS verify: (Optional) Disable certificate verification when TLS is enabled. Use only for self-signed development clusters.
• Authority: (Optional) Override the :authority pseudo-header. Useful when probing through a host-routing proxy or service mesh.

Example Use Cases

• Internal microservices: Probe each backend's standard health service to catch upstream rollouts that miss readiness gates.
• Service mesh sidecars: Verify Envoy or Istio-fronted services are reachable end-to-end through the mesh by overriding the :authority header.
• Multi-tenant gRPC servers: Track per-service health (Service field) on a server that hosts several gRPC services in a single process.

Notes

• The monitor reports the returned health status (e.g., SERVING, NOT_SERVING, UNKNOWN) in result metadata for richer dashboards and alerting.
• Servers that do not implement grpc.health.v1.Health will return Unimplemented and the check will report Down — implement the standard health service or use a TCP monitor instead.