Prisma Connection Pool Exhaustion in Serverless

Problem

Serverless functions create a new Prisma client instance on each cold start. Each instance opens multiple database connections (default: 5 per instance). With many concurrent requests, this quickly exhausts the database's connection limit (often 20-100 for managed databases).

Context / Trigger Conditions

This skill applies when you see:

• P2024: Timed out fetching a new connection from the connection pool
• PostgreSQL: FATAL: too many connections for role "username"
• MySQL: Too many connections
• Works fine locally with npm run dev but fails in production
• Errors appear during traffic spikes, then resolve
• Database dashboard shows connections at or near limit