Applications and operations
Budget connection pools
Limit connections across all application replicas and preserve room for workers, migrations, and emergency access.
8 minute lesson
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Create one bounded pool in each application process:
import pg from 'pg'
const { Pool } = pg
export const pool = new Pool({
connectionString: process.env.DATABASE_URL,
max: 5,
connectionTimeoutMillis: 5000,
idleTimeoutMillis: 30000,
statement_timeout: 10000,
application_name: 'notes-web',
})Five connections is an example budget. Eight replicas with a pool of five can still request forty connections.
Leave room for workers, migrations, and emergency access. Call await pool.end() when a script or worker shuts down.
Lesson completed