Evernote Observability

Overview

Comprehensive observability setup for Evernote integrations: Prometheus metrics for API call tracking, structured JSON logging, OpenTelemetry tracing, health check endpoints, and alerting rules.

Prerequisites

• Monitoring infrastructure (Prometheus, Datadog, or CloudWatch)
• Log aggregation (ELK, Loki, or CloudWatch Logs)
• Alerting system (PagerDuty, Opsgenie, or Slack webhooks)

Instructions

Step 1: Metrics Collection

Track key metrics with Prometheus counters and histograms: evernote_api_calls_total (by method and status), evernote_api_duration_seconds (latency histogram), evernote_rate_limits_total (rate limit hits), evernote_quota_usage_bytes (upload quota consumption).

const { Counter, Histogram } = require('prom-client');

const apiCalls = new Counter({
  name: 'evernote_api_calls_total',
  help: 'Total Evernote API calls',
  labelNames: ['method', 'status']
});

const apiDuration = new Histogram({
  name: 'evernote_api_duration_seconds',
  help: 'Evernote API call duration',
  labelNames: ['method'],
  buckets: [0.1, 0.5, 1, 2, 5, 10]
});

Step 2: Instrumented Client

Wrap the NoteStore with a Proxy that automatically records metrics for every API call. Increment counters on success/failure, observe latency in histograms, and count rate limit events.

Step 3: Structured Logging

Use JSON-formatted logs with consistent fields: timestamp, level, method, duration, userId (hashed), noteGuid. Redact access tokens from all log output.

function logApiCall(method, duration, error) {
  const entry = {
    timestamp: new Date().toISOString(),
    service: 'evernote-integration',
    method,
    duration_ms: duration,
    status: error ? 'error' : 'success',
    error_code: error?.errorCode
  };
  console.log(JSON.stringify(entry));
}

Step 4: Health and Readiness Endpoints

Implement /health (liveness: is the process running?) and /ready (readiness: can we reach Evernote API?). Include cache connectivity check.

Step 5: Alert Rules

Configure Prometheus alerts: rate limit hits > 5 in 10 minutes, API error rate > 10%, p95 latency > 5 seconds, quota usage > 90%.

# prometheus-alerts.yml
groups:
  - name: evernote
    rules:
      - alert: EvernoteRateLimited
        expr: rate(evernote_rate_limits_total[10m]) > 0.5
        for: 5m
        labels: { severity: warning }
        annotations:
          summary: "Evernote rate limits detected"

For the complete metrics setup, Grafana dashboard JSON, tracing configuration, and alert rules, see Implementation Guide.

Output

• Prometheus metrics: API calls, latency histogram, rate limits, quota usage
• Instrumented NoteStore client with automatic metric recording
• Structured JSON logging with token redaction
• Health and readiness endpoints
• Prometheus alert rules for rate limits, errors, and latency

Error Handling

Error	Cause	Solution
Metrics endpoint not scraped	Prometheus target missing	Add service to Prometheus scrape config
Missing trace context	OpenTelemetry not initialized	Initialize tracer before creating Evernote client
Log volume too high	Logging every API call	Sample debug logs, always log errors and rate limits
Alert fatigue	Thresholds too low	Tune alert thresholds based on baseline metrics

Resources

• Prometheus
• OpenTelemetry Node.js
• Grafana
• prom-client npm

Next Steps

For incident handling, see evernote-incident-runbook.

Examples

Grafana dashboard: Display API call rate, p50/p95/p99 latency, error rate, rate limit frequency, and quota usage on a single dashboard. Set time range to last 24 hours.

Rate limit alerting: Alert on-call when rate limit hits exceed 5 per 10-minute window. Include runbook link to evernote-rate-limits in the alert annotation.