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Troubleshooting

Database Connection Pooling​

Open Mercato relies on PostgreSQL connection pooling to avoid "too many clients" errors. Tune the pool via environment variables to match your deployment footprint.

Pool Configuration​

  • DB_POOL_MIN — Minimum connections in the pool (default: 2)
  • DB_POOL_MAX — Maximum connections in the pool (default: 10)
  • DB_POOL_IDLE_TIMEOUT — Idle timeout in milliseconds before a connection is released (default: 30000)
  • DB_POOL_ACQUIRE_TIMEOUT — Acquire timeout in milliseconds when waiting for a connection (default: 60000)

Production baseline:

# Adjust according to PostgreSQL max_connections
DB_POOL_MAX=20
DB_POOL_MIN=5
DB_POOL_IDLE_TIMEOUT=30000
DB_POOL_ACQUIRE_TIMEOUT=60000

Local development:

# Smaller pool for local workflows
DB_POOL_MAX=5
DB_POOL_MIN=1
DB_POOL_IDLE_TIMEOUT=10000
DB_POOL_ACQUIRE_TIMEOUT=30000

If you continue to hit connection limits, verify that background workers and migrations use the same pool settings, and confirm that your database max_connections value comfortably exceeds the aggregate pool size across all applications connecting to it.