Exa Load & Scale

Overview

Load testing and capacity planning for Exa integrations. Key constraint: Exa's default rate limit is 10 QPS. Scaling strategies focus on caching, request queuing, parallel processing within rate limits, and search type selection for latency budgets.

Prerequisites

• k6 load testing tool installed
• Test environment Exa API key (separate from production)
• Redis for result caching

Capacity Reference

Search Type	Typical Latency	Max Throughput (10 QPS)
instant	< 150ms	10 req/s (600/min)
fast	< 425ms	10 req/s (600/min)
auto	300-1500ms	10 req/s (600/min)
neural	500-2000ms	10 req/s (600/min)
deep	2-5s	10 req/s (600/min)

With caching (50% hit rate): Effective throughput doubles to 20 req/s equivalent.

Instructions

Step 1: k6 Load Test Against Your Wrapper

// exa-load-test.js
import http from "k6/http";
import { check, sleep } from "k6";

export const options = {
  stages: [
    { duration: "1m", target: 5 },    // Ramp up to 5 VUs
    { duration: "3m", target: 5 },    // Steady state
    { duration: "1m", target: 10 },   // Push toward rate limit
    { duration: "2m", target: 10 },   // Stress test
    { duration: "1m", target: 0 },    // Ramp down
  ],
  thresholds: {
    http_req_duration: ["p(95)<3000"],  // 3s P95 for neural search
    http_req_failed: ["rate<0.05"],     // < 5% error rate
  },
};

const queries = [
  "best practices for building RAG systems",
  "transformer architecture improvements 2025",
  "TypeScript 5.5 new features",
  "vector database comparison guide",
  "AI safety alignment research",
];

export default function () {
  const query = queries[Math.floor(Math.random() * queries.length)];

  const response = http.post(
    `${__ENV.APP_URL}/api/search`,
    JSON.stringify({ query, numResults: 3 }),
    {
      headers: { "Content-Type": "application/json" },
      timeout: "10s",
    }
  );

  check(response, {
    "status 200": (r) => r.status === 200,
    "has results": (r) => JSON.parse(r.body).results?.length > 0,
    "latency < 3s": (r) => r.timings.duration < 3000,
  });

  sleep(0.5 + Math.random()); // 0.5-1.5s between requests
}

# Run load test
k6 run --env APP_URL=http://localhost:3000 exa-load-test.js

Step 2: Throughput Maximizer with Request Queue

import Exa from "exa-js";
import PQueue from "p-queue";

const exa = new Exa(process.env.EXA_API_KEY);

// Stay under 10 QPS rate limit
const searchQueue = new PQueue({
  concurrency: 8,        // max concurrent requests
  interval: 1000,        // per second
  intervalCap: 10,       // Exa's QPS limit
});

async function highThroughputSearch(queries: string[]) {
  const results = [];

  for (const query of queries) {
    const promise = searchQueue.add(async () => {
      const result = await exa.searchAndContents(query, {
        type: "auto",
        numResults: 3,
        text: { maxCharacters: 500 },
      });
      return { query, results: result.results };
    });
    results.push(promise);
  }

  return Promise.all(results);
}

// Process 100 queries respecting rate limits
const queries = Array.from({ length: 100 }, (_, i) => `research topic ${i}`);
console.time("batch");
const results = await highThroughputSearch(queries);
console.timeEnd("batch");
// Expected: ~10-12 seconds (100 queries / 10 QPS)

Step 3: Caching for Scale

import { LRUCache } from "lru-cache";

// Cache eliminates repeat queries entirely
const cache = new LRUCache<string, any>({
  max: 10000,
  ttl: 3600 * 1000, // 1-hour TTL
});

async function scalableSearch(query: string, opts: any) {
  const key = `${query.toLowerCase().trim()}:${opts.type}:${opts.numResults}`;
  const cached = cache.get(key);
  if (cached) return cached;

  const result = await searchQueue.add(() =>
    exa.searchAndContents(query, opts)
  );
  cache.set(key, result);
  return result;
}

// With 50% cache hit rate:
// 100 unique queries → 50 API calls → 5 seconds instead of 10

Step 4: Capacity Planning Calculator

interface CapacityEstimate {
  dailySearches: number;
  peakQPS: number;
  cacheHitRate: number;
  effectiveQPS: number;
  withinLimits: boolean;
  recommendation: string;
}

function estimateCapacity(
  dailySearches: number,
  peakMultiplier = 3,
  expectedCacheHitRate = 0.5
): CapacityEstimate {
  const avgQPS = dailySearches / (24 * 3600);
  const peakQPS = avgQPS * peakMultiplier;
  const effectiveQPS = peakQPS * (1 - expectedCacheHitRate);
  const withinLimits = effectiveQPS <= 10; // Default Exa limit

  let recommendation = "Within default limits";
  if (effectiveQPS > 10 && effectiveQPS <= 50) {
    recommendation = "Contact hello@exa.ai for Enterprise rate limits";
  } else if (effectiveQPS > 50) {
    recommendation = "Requires Enterprise plan + aggressive caching + request queue";
  }

  return { dailySearches, peakQPS, cacheHitRate: expectedCacheHitRate, effectiveQPS, withinLimits, recommendation };
}

// Example: 50,000 searches/day
const estimate = estimateCapacity(50000);
console.log(estimate);
// { effectiveQPS: ~0.87, withinLimits: true, recommendation: "Within default limits" }

Benchmark Results Template

## Exa Performance Benchmark
**Date:** YYYY-MM-DD | **SDK:** exa-js X.Y.Z

| Metric | Value |
|--------|-------|
| Total Requests | N |
| Success Rate | X% |
| Cache Hit Rate | X% |
| P50 Latency | Xms |
| P95 Latency | Xms |
| Peak QPS (actual API calls) | X |
| 429 Rate Limit Errors | N |

Error Handling

Issue	Cause	Solution
429 errors in load test	Exceeding 10 QPS	Reduce concurrency, add cache
Inconsistent latency	Different search types	Standardize on one type per test
Timeout errors	Deep search under load	Use fast or auto for load tests
Cache miss rate high	Unique queries per request	Use a fixed query pool

Resources

• Exa Rate Limits
• k6 Documentation
• p-queue

Next Steps

For reliability patterns, see exa-reliability-patterns.