replit-load-scale

# Replit Load & Scale ## Overview Load testing, scaling strategies, and capacity planning for Replit integrations. ## Prerequisites - k6 load testing tool installed - Kubernetes cluster with HPA configured - Prometheus for metrics collection - Test environment API keys ## Load Testing with k6 ### Basic Load Test ```javascript // replit-load-test.js import http from 'k6/http'; import { check, sleep } from 'k6'; export const options = { stages: [ { duration: '2m', target: 10 }, // Ramp up { duration: '5m', target: 10 }, // Steady state { duration: '2m', target: 50 }, // Ramp to peak { duration: '5m', target: 50 }, // Stress test { duration: '2m', target: 0 }, // Ramp down ], thresholds: { http_req_duration: ['p(95)<500'], http_req_failed: ['rate<0.01'], }, }; export default function () { const response = http.post( 'https://api.replit.com/v1/resource', JSON.stringify({ test: true }), { headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${__ENV.REPLIT_API_KEY}`, }, } ); check(response, { 'status is 200': (r) => r.status === 200, 'latency < 500ms': (r) => r.timings.duration < 500, }); sleep(1); } ``` ### Run Load Test ```bash # Install k6 brew install k6 # macOS # or: sudo apt install k6 # Linux # Run test k6 run --env REPLIT_API_KEY=${REPLIT_API_KEY} replit-load-test.js # Run with output to InfluxDB k6 run --out influxdb=http://localhost:8086/k6 replit-load-test.js ``` ## Scaling Patterns ### Horizontal Scaling ```yaml # kubernetes HPA apiVersion: autoscaling/v2 kind: HorizontalPodAutoscaler metadata: name: replit-integration-hpa spec: scaleTargetRef: apiVersion: apps/v1 kind: Deployment name: replit-integration minReplicas: 2 maxReplicas: 20 metrics: - type: Resource resource: name: cpu target: type: Utilization averageUtilization: 70 - type: Pods pods: metric: name: replit_queue_depth target: type: AverageValue averageValue: 100 ``` ### Connection Pooling ```typescript import { Pool } from 'generic-pool'; const replitPool = Pool.create({ create: async () => { return new ReplitClient({ apiKey: process.env.REPLIT_API_KEY!, }); }, destroy: async (client) => { await client.close(); }, max: 20, min: 5, idleTimeoutMillis: 30000, }); async function withReplitClient( fn: (client: ReplitClient) => Promise ): Promise { const client = await replitPool.acquire(); try { return await fn(client); } finally { replitPool.release(client); } } ``` ## Capacity Planning ### Metrics to Monitor | Metric | Warning | Critical | |--------|---------|----------| | CPU Utilization | > 70% | > 85% | | Memory Usage | > 75% | > 90% | | Request Queue Depth | > 100 | > 500 | | Error Rate | > 1% | > 5% | | P95 Latency | > 1000ms | > 3000ms | ### Capacity Calculation ```typescript interface CapacityEstimate { currentRPS: number; maxRPS: number; headroom: number; scaleRecommendation: string; } function estimateReplitCapacity( metrics: SystemMetrics ): CapacityEstimate { const currentRPS = metrics.requestsPerSecond; const avgLatency = metrics.p50Latency; const cpuUtilization = metrics.cpuPercent; // Estimate max RPS based on current performance const maxRPS = currentRPS / (cpuUtilization / 100) * 0.7; // 70% target const headroom = ((maxRPS - currentRPS) / currentRPS) * 100; return { currentRPS, maxRPS: Math.floor(maxRPS), headroom: Math.round(headroom), scaleRecommendation: headroom < 30 ? 'Scale up soon' : headroom < 50 ? 'Monitor closely' : 'Adequate capacity', }; } ``` ## Benchmark Results Template ```markdown ## Replit Performance Benchmark **Date:** YYYY-MM-DD **Environment:** [staging/production] **SDK Version:** X.Y.Z ### Test Configuration - Duration: 10 minutes - Ramp: 10 → 100 → 10 VUs - Target endpoint: /v1/resource ### Results | Metric | Value | |--------|-------| | Total Requests | 50,000 | | Success Rate | 99.9% | | P50 Latency | 120ms | | P95 Latency | 350ms | | P99 Latency | 800ms | | Max RPS Achieved | 150 | ### Observations - [Key finding 1] - [Key finding 2] ### Recommendations - [Scaling recommendation] ``` ## Instructions ### Step 1: Create Load Test Script Write k6 test script with appropriate thresholds. ### Step 2: Configure Auto-Scaling Set up HPA with CPU and custom metrics. ### Step 3: Run Load Test Execute test and collect metrics. ### Step 4: Analyze and Document Record results in benchmark template. ## Output - Load test script created - HPA configured - Benchmark results documented - Capacity recommendations defined ## Error Handling | Issue | Cause | Solution | |-------|-------|----------| | k6 timeout | Rate limited | Reduce RPS | | HPA not scaling | Wrong metrics | Verify metric name | | Connection refused | Pool exhausted | Increase pool size | | Inconsistent results | Warm-up needed | Add ramp-up phase | ## Examples ### Quick k6 Test ```bash k6 run --vus 10 --duration 30s replit-load-test.js ``` ### Check Current Capacity ```typescript const metrics = await getSystemMetrics(); const capacity = estimateReplitCapacity(metrics); console.log('Headroom:', capacity.headroom + '%'); console.log('Recommendation:', capacity.scaleRecommendation); ``` ### Scale HPA Manually ```bash kubectl scale deployment replit-integration --replicas=5 kubectl get hpa replit-integration-hpa ``` ## Resources - [k6 Documentation](https://k6.io/docs/) - [Kubernetes HPA](https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/) - [Replit Rate Limits](https://docs.replit.com/rate-limits) ## Next Steps For reliability patterns, see `replit-reliability-patterns`.