PG-REC-CONN-001 · Connections near max_connections

Severity	Confidence	Permission	Applies to
High	Confirmed	pg_monitor (pg_read_all_stats)	Recordings (codedb-lens record): PostgreSQL 14+, RDS, Aurora, Azure Flexible

What it checks

The connections collector: client connections as a percentage of max_connections minus superuser_reserved_connections. An episode is two or more samples in a row at 90% or more (max_pct).

Why it matters

Client connections used 90% or more of the usable slots for at least 30 seconds. When they run out, new connections fail with "too many clients" and the application stops.

Next action

Look at how many of those connections were idle or idle in transaction. Many idle connections call for a pooler (PgBouncer) or smaller application pools, not a higher max_connections.

How to verify

Record again during the same hours after the change. Connections must stay well below max_connections.

Limitations

The limit shown is max_connections minus superuser_reserved_connections; on PostgreSQL 16+ reserved_connections also takes slots and is not subtracted.