posthog-performance-tuning

# PostHog Performance Tuning ## Overview Optimize PostHog API performance with caching, batching, and connection pooling. ## Prerequisites - PostHog SDK installed - Understanding of async patterns - Redis or in-memory cache available (optional) - Performance monitoring in place ## Latency Benchmarks | Operation | P50 | P95 | P99 | |-----------|-----|-----|-----| | Read | 50ms | 150ms | 300ms | | Write | 100ms | 250ms | 500ms | | List | 75ms | 200ms | 400ms | ## Caching Strategy ### Response Caching ```typescript import { LRUCache } from 'lru-cache'; const cache = new LRUCache({ max: 1000, ttl: 60000, // 1 minute updateAgeOnGet: true, }); async function cachedPostHogRequest( key: string, fetcher: () => Promise, ttl?: number ): Promise { const cached = cache.get(key); if (cached) return cached as T; const result = await fetcher(); cache.set(key, result, { ttl }); return result; } ``` ### Redis Caching (Distributed) ```typescript import Redis from 'ioredis'; const redis = new Redis(process.env.REDIS_URL); async function cachedWithRedis( key: string, fetcher: () => Promise, ttlSeconds = 60 ): Promise { const cached = await redis.get(key); if (cached) return JSON.parse(cached); const result = await fetcher(); await redis.setex(key, ttlSeconds, JSON.stringify(result)); return result; } ``` ## Request Batching ```typescript import DataLoader from 'dataloader'; const posthogLoader = new DataLoader( async (ids) => { // Batch fetch from PostHog const results = await posthogClient.batchGet(ids); return ids.map(id => results.find(r => r.id === id) || null); }, { maxBatchSize: 100, batchScheduleFn: callback => setTimeout(callback, 10), } ); // Usage - automatically batched const [item1, item2, item3] = await Promise.all([ posthogLoader.load('id-1'), posthogLoader.load('id-2'), posthogLoader.load('id-3'), ]); ``` ## Connection Optimization ```typescript import { Agent } from 'https'; // Keep-alive connection pooling const agent = new Agent({ keepAlive: true, maxSockets: 10, maxFreeSockets: 5, timeout: 30000, }); const client = new PostHogClient({ apiKey: process.env.POSTHOG_API_KEY!, httpAgent: agent, }); ``` ## Pagination Optimization ```typescript async function* paginatedPostHogList( fetcher: (cursor?: string) => Promise<{ data: T[]; nextCursor?: string }> ): AsyncGenerator { let cursor: string | undefined; do { const { data, nextCursor } = await fetcher(cursor); for (const item of data) { yield item; } cursor = nextCursor; } while (cursor); } // Usage for await (const item of paginatedPostHogList(cursor => posthogClient.list({ cursor, limit: 100 }) )) { await process(item); } ``` ## Performance Monitoring ```typescript async function measuredPostHogCall( operation: string, fn: () => Promise ): Promise { const start = performance.now(); try { const result = await fn(); const duration = performance.now() - start; console.log({ operation, duration, status: 'success' }); return result; } catch (error) { const duration = performance.now() - start; console.error({ operation, duration, status: 'error', error }); throw error; } } ``` ## Instructions ### Step 1: Establish Baseline Measure current latency for critical PostHog operations. ### Step 2: Implement Caching Add response caching for frequently accessed data. ### Step 3: Enable Batching Use DataLoader or similar for automatic request batching. ### Step 4: Optimize Connections Configure connection pooling with keep-alive. ## Output - Reduced API latency - Caching layer implemented - Request batching enabled - Connection pooling configured ## Error Handling | Issue | Cause | Solution | |-------|-------|----------| | Cache miss storm | TTL expired | Use stale-while-revalidate | | Batch timeout | Too many items | Reduce batch size | | Connection exhausted | No pooling | Configure max sockets | | Memory pressure | Cache too large | Set max cache entries | ## Examples ### Quick Performance Wrapper ```typescript const withPerformance = (name: string, fn: () => Promise) => measuredPostHogCall(name, () => cachedPostHogRequest(`cache:${name}`, fn) ); ``` ## Resources - [PostHog Performance Guide](https://docs.posthog.com/performance) - [DataLoader Documentation](https://github.com/graphql/dataloader) - [LRU Cache Documentation](https://github.com/isaacs/node-lru-cache) ## Next Steps For cost optimization, see `posthog-cost-tuning`.