Programming Tutorials

  You deploy a Supabase Edge Function. It works perfectly during testing. Then, you launch. Traffic spikes, thousands of users hit your endpoint simultaneously, and your logs fill with the dreaded PostgreSQL error: FATAL: remaining connection slots are reserved for non-replication superuser connections Or simply:  FATAL: sorry, too many clients already . Your serverless functions are scaling, but your database is crashing. This is the classic "Serverless vs. Stateful" impedance mismatch. In this guide, we will solve this by implementing Supabase’s connection pooler correctly, distinguishing between Port 6543 and 5432, and forcing Transaction Mode to handle high concurrency. The Root Cause: Why Serverless Kills Postgres To fix the problem, you must understand the architecture of the failure. PostgreSQL uses a process-based model. For every established connection, the database spins up a new backend process. This process consumes a significant amount of RAM (roughly 2-10MB per ...