RDS Connection Limits for db.t4g.medium

Connection limits depend on the database engine, parameter group settings, and instance memory. AWS defaults are formula-based, but you can override them in your parameter group.

PostgreSQL, MySQL, and MariaDB use different formulas for max_connections, so the same instance size can yield different defaults. Always confirm the effective value for your engine and version.

Treat limits as planning guidance: real workloads, pooling behavior, and reserved connections for operations can materially change the safe budget.

Example: if the usable budget is 400 connections and you plan for 10 pods, the target pool size is 400 ÷ 10 = 40 per pod before adding headroom.

Estimate your budget

Use the estimator to model pods, pool sizes, and headroom before you scale.