How to Monitor gRPC APIs with Vigilmon

gRPC has become the go-to protocol for high-performance, internal service communication — especially in microservices architectures where latency matters. But its binary protocol and streaming capabilities make monitoring significantly different from standard HTTP APIs. If a gRPC service goes down or starts degrading, you need to know before your customers do.

This guide walks you through monitoring your gRPC APIs with Vigilmon, a developer-first uptime monitoring tool with a free tier that requires no credit card.

Why gRPC Monitoring Is Different

Unlike REST APIs, gRPC uses HTTP/2 and Protocol Buffers. Traditional ping-based monitors won't cut it — they can't introspect gRPC health status. However, most production gRPC services expose:

• A gRPC health check endpoint (via the standard grpc.health.v1.Health protocol)
• An HTTP/1.1 health endpoint (e.g., /healthz) alongside the gRPC server
• Metrics endpoints (e.g., Prometheus /metrics)

Vigilmon's HTTP monitors can target these companion endpoints, giving you reliable uptime data without needing a native gRPC client.

Setting Up gRPC Monitoring with Vigilmon

Step 1: Expose an HTTP Health Endpoint

If your gRPC service doesn't already have one, add a lightweight HTTP health endpoint. Here's a Go example:

http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
    w.WriteHeader(http.StatusOK)
    w.Write([]byte("ok"))
})
go http.ListenAndServe(":8080", nil)

In Node.js with @grpc/grpc-js, you'd spin up a small Express app on a separate port alongside your gRPC server.

Step 2: Create a Vigilmon Account

Head to vigilmon.online and sign up for free. The free tier gives you 10 monitors with 3-minute check intervals — no credit card required.

Step 3: Add an HTTP Monitor

In the Vigilmon dashboard:

1. Click Add Monitor
2. Select HTTP monitor type
3. Enter the URL for your health endpoint (e.g., https://api.yourservice.com:8080/healthz)
4. Set the check interval (3 minutes on free, down to 1 minute on paid plans)
5. Set expected status code to 200
6. Enable multi-region checks (Vigilmon monitors from US, EU, and AP regions)

Step 4: Monitor the gRPC Port Directly with TCP

Even if your gRPC health endpoint is HTTP-based, add a TCP monitor on the gRPC port (default: 50051):

1. Add a second monitor
2. Select TCP type
3. Enter yourservice.com:50051

This catches cases where the HTTP sidecar is up but the gRPC listener itself is down.

Step 5: Set Up Alerts

Navigate to Alert Settings and configure:

• Email for immediate notification
• Slack or Discord for team channels
• PagerDuty for on-call escalation
• Webhooks to trigger automated remediation pipelines

Key Metrics to Monitor for gRPC Services

Beyond basic uptime, you should track:

Metric	What It Tells You
Response time	Latency of your health endpoint proxy
TCP connect time	Raw network + process startup overhead
Uptime % per region	Detects regional routing failures
Time to first byte (TTFB)	Early indicator of gRPC server backpressure

Vigilmon's dashboard surfaces response time trends over time, so you can spot gradual degradation before it becomes an outage.

Alert Configuration Tips

Avoid alert fatigue: Configure a confirmation window — Vigilmon can confirm a failure from multiple regions before paging you. A blip in one region isn't necessarily a real outage.

Separate monitors per environment: Run distinct monitors for staging and production. This helps you catch issues in staging before they reach prod.

Set response-time thresholds: Even when your service returns 200, a response time spike (e.g., > 2 seconds on a health check) can signal upstream congestion or database contention.

Beyond Uptime: Heartbeat Monitors for gRPC Workers

If you have gRPC workers processing background jobs (e.g., event consumers), use Vigilmon's heartbeat monitor to verify they're running. Your worker pings Vigilmon's heartbeat URL periodically; if the ping stops, you get alerted.

Why Vigilmon for gRPC?

• Free tier: 10 monitors, 3-minute intervals, no credit card
• Paid plans from $6/month for higher frequency and more monitors
• Multi-region: US, EU, AP checks out of the box
• All alert channels: Email, Slack, Discord, webhooks, PagerDuty
• Simple setup: No agents, no SDKs — just a URL

Get Started

Don't wait for a user to report your gRPC service is down. Set up monitoring in under 5 minutes at vigilmon.online — it's free to start.

Whether you're running a simple two-service architecture or a sprawling microservices mesh, having reliable uptime checks on every gRPC endpoint is non-negotiable. Vigilmon makes it easy.