Client Metrics

Internal documentation for the NetBird client metrics system.

Overview

Client metrics track connection performance and sync durations using InfluxDB line protocol (influxdb.go). Each event is pushed once then cleared.

Metrics collection is always active (for debug bundles). Push to backend is:

• Disabled by default (opt-in via NB_METRICS_PUSH_ENABLED=true)
• Managed at daemon layer (survives engine restarts)

Architecture

Layer Separation

Daemon Layer (connect.go)
  ├─ Creates ClientMetrics instance once
  ├─ Starts/stops push lifecycle
  └─ Updates AgentInfo on profile switch
      │
      ▼
Engine Layer (engine.go)
  └─ Records metrics via ClientMetrics methods

Ingest Server

Clients do not talk to InfluxDB directly. An ingest server sits between clients and InfluxDB:

Client ──POST──▶ Ingest Server (:8087) ──▶ InfluxDB (internal)
                  │
                  ├─ Validates line protocol
                  ├─ Allowlists measurements, fields, and tags
                  ├─ Rejects out-of-bound values
                  └─ Serves remote config at /config

• No secret/token-based client auth — the ingest server holds the InfluxDB token server-side. Clients must send a hashed peer ID via X-Peer-ID header.
• InfluxDB is not exposed — only accessible within the docker network
• Source: ingest/main.go

Metrics Collected

Connection Stage Timing

Measurement: netbird_peer_connection

Tags:

• deployment_type: "cloud" | "selfhosted" | "unknown"
• connection_type: "ice" | "relay"
• attempt_type: "initial" | "reconnection"
• version: NetBird version string
• os: Operating system (linux, darwin, windows, android, ios, etc.)
• arch: CPU architecture (amd64, arm64, etc.)

Note: SignalingReceived is set when the first offer or answer arrives from the remote peer (in both initial and reconnection paths). It excludes the potentially unbounded wait for the remote peer to come online.

Sync Duration

Measurement: netbird_sync

Tags:

• deployment_type: "cloud" | "selfhosted" | "unknown"
• version: NetBird version string
• os: Operating system (linux, darwin, windows, android, ios, etc.)
• arch: CPU architecture (amd64, arm64, etc.)

Sync Phase Timing

Measurement: netbird_sync_phase

Breaks down where time goes inside a single sync, so the total netbird_sync duration can be attributed to the sub-step that dominates.

Tags:

• phase: the sub-phase — netbird_config, checks, persist, dns_server, routes_classify, routes_apply, filtering, dns_forwarder, forward_rules, offline_peers, removed_peers, modified_peers, added_peers, lazy_exclude
• deployment_type: "cloud" | "selfhosted" | "unknown"
• version: NetBird version string
• os: Operating system (linux, darwin, windows, android, ios, etc.)
• arch: CPU architecture (amd64, arm64, etc.)

Note: this is wall-time per phase — it includes both CPU work and time spent waiting on locks. A slow phase points to where the time goes, not why; pair it with lock-wait metrics to tell contention apart from real work.

Login Duration

Measurement: netbird_login

Tags:

• deployment_type: "cloud" | "selfhosted" | "unknown"
• result: "success" | "failure"
• version: NetBird version string
• os: Operating system (linux, darwin, windows, android, ios, etc.)
• arch: CPU architecture (amd64, arm64, etc.)

Buffer Limits

The InfluxDB backend limits in-memory sample storage to prevent unbounded growth when pushes fail:

• Max age: Samples older than 5 days are dropped
• Max size: Estimated buffer size capped at 5 MB (~20k samples)

Configuration

Client Environment Variables

NB_METRICS_SERVER_URL and NB_METRICS_INTERVAL override their respective values but do not bypass remote config eligibility checks (version range). Use NB_METRICS_FORCE_SENDING=true to skip all remote config gating.

Ingest Server Environment Variables

The ingest server serves a remote config JSON at GET /config when CONFIG_METRICS_SERVER_URL is set. Clients can use NB_METRICS_CONFIG_URL=http://<ingest>/config to fetch it.

Configuration Precedence

For URL and Interval, the precedence is:

1. Environment variable - NB_METRICS_SERVER_URL / NB_METRICS_INTERVAL
2. Remote config - fetched from NB_METRICS_CONFIG_URL
3. Default - 5 minute interval, URL from remote config

Push Behavior

1. StartPush() spawns background goroutine with timer
2. First push happens immediately on startup
3. Periodically: push() → Export() → HTTP POST to ingest server
4. On failure: log error, continue (non-blocking)
5. On success: Reset() clears pushed samples
6. StopPush() cancels context and waits for goroutine

Samples are collected with exact timestamps, pushed once, then cleared. No data is resent.

Local Development Setup

1. Configure and Start Services

# From this directory (client/internal/metrics/infra)
cp .env.example .env
# Edit .env to set INFLUXDB_ADMIN_PASSWORD, INFLUXDB_ADMIN_TOKEN, and GRAFANA_ADMIN_PASSWORD
docker compose up -d

This starts:

• Ingest server on http://localhost:8087 — accepts client metrics (requires X-Peer-ID header, no secret/token auth)
• InfluxDB — internal only, not exposed to host
• Grafana on http://localhost:3001

2. Configure Client

export NB_METRICS_PUSH_ENABLED=true
export NB_METRICS_FORCE_SENDING=true
export NB_METRICS_SERVER_URL=http://localhost:8087
export NB_METRICS_INTERVAL=1m

3. Run Client

cd ../../../..
go run ./client/ up

4. View in Grafana

• InfluxDB dashboard: http://localhost:3001/d/netbird-influxdb-metrics

5. Verify Data

# Query via InfluxDB (using admin token from .env)
docker compose exec influxdb influx query \
  'from(bucket: "metrics") |> range(start: -1h)' \
  --org netbird

# Check ingest server health
curl http://localhost:8087/health

Analyzing a Debug Bundle

Metrics collection is always on, so every debug bundle ships a metrics.txt in InfluxDB line protocol — a timestamped time series of all recorded events (sync durations, sync phases, connection stages, login). You can replay it into the local stack and graph it, without a running client.

The bundle's metrics.txt is a rolling window (capped at 5 days / ~20k samples, see Buffer Limits). For a connection incident the relevant window is short (connection setup is seconds), so a bundle captured during the issue is enough.

1. Start the stack

# From this directory (client/internal/metrics/infra)
INFLUXDB_ADMIN_TOKEN=admin123 INFLUXDB_ADMIN_PASSWORD=admin123 GRAFANA_ADMIN_PASSWORD=admin123 \
  docker compose up -d

(admin123 are throwaway local credentials — fine for offline analysis.)

2. Clear any previous data

So you only see this bundle:

docker exec influxdb influx delete --org netbird --bucket metrics --token admin123 \
  --start 1970-01-01T00:00:00Z --stop 2100-01-01T00:00:00Z

3. Import the bundle's metrics.txt

InfluxDB is not exposed on the host, so import inside the container:

docker cp /path/to/bundle/metrics.txt influxdb:/tmp/m.txt
docker exec influxdb influx write --org netbird --bucket metrics --precision ns \
  --token admin123 --file /tmp/m.txt

Re-importing the same file is idempotent (same measurement+tags+timestamp overwrites).

4. View the dashboards

Grafana on http://localhost:3001 (login admin / admin123), datasource pre-provisioned:

• Where sync time goes: http://localhost:3001/d/netbird-sync-phases/netbird-sync-phases-where-time-goes
• General client metrics: http://localhost:3001/d/netbird-influxdb-metrics

Set the time range to cover the bundle's timestamps (e.g. "Last 7 days" or an absolute range matching when the bundle was taken) — with the default short range the panels look empty.

Bundles are distinguishable by the version tag; add a tag at import time (e.g. sed 's/^netbird_\([a-z_]*\),/netbird_\1,bundle=mycase,/' metrics.txt) if you want to compare several side by side.