Chapter 5: Optimizing Golang Database Connection Pools
Multi-Language Edition: This chapter is also available in Vietnamese at 📖 Bản tiếng Việt (Vietnamese Edition). Previous: Chapter 4 — Dual-Write Prevention via Transactional Outbox | Series Hub | Next: Chapter 6 — API Gateway vs Service Mesh in Microservices Answer-First: Unbounded database connection pools in Go microservices quickly exhaust PostgreSQL’s process-per-connection architecture, triggering severe CPU context switching and memory exhaustion. The battle-tested production formula: (1) In Go’s *sql.DB, set SetMaxOpenConns dynamically based on Little’s Law ($C = \lambda \times W$), set SetMaxIdleConns == SetMaxOpenConns to eliminate constant TCP three-way handshakes, and set SetConnMaxLifetime below cloud NAT idle timeouts; (2) In front of PostgreSQL, place a dedicated connection pooler (PgBouncer or Pgcat) in Transaction Pooling mode to multiplex 20,000 application sockets over just 50 to 100 backend database connections. ...