The Connection Usage % alert notifies you when its configured condition is met on PostgreSQL instances so you can investigate and respond.
Mini DBA describes this alert as: Percentage of configured max_connections currently in use. High values can reject new client work and usually need pooling or capacity review. Mini DBA evaluates this alert once a minute so changes are detected quickly. Because duration is used, Mini DBA can avoid treating a single short spike as a full incident when the condition clears quickly.
This alert warns that client connections or database sessions are approaching a configured capacity limit. Reaching the limit can reject new work even when CPU and storage still have headroom.
Enable it where exhausting the connection or session limit would interrupt application traffic. Establish a normal concurrency baseline first, then leave enough warning margin to diagnose connection leaks, login storms, or undersized limits.
Threshold meaning: % of max_connections. Major threshold: 95 %. Minor threshold: 85 %. Comparison direction: over. Duration is used, so prefer requiring the condition to persist before paging people for transient spikes. For an over-threshold alert, decreasing a threshold makes that severity fire sooner; increasing it tolerates more load or pressure. Set the minor threshold as an early-warning level and the major threshold at the highest acceptable value for the service.
Identify which applications and logins own the open sessions, then check connection-pool reuse, idle-session lifetime, retry storms, and recent traffic changes. Correct leaks or churn before increasing the engine limit, and raise the limit only when host capacity and platform guidance support it.
If the alert creates repeated noise, review whether it is enabled on the correct instances, whether maintenance windows are configured, and whether the minor and major routes match the real business impact. Keep enough history to prove the new setting before changing it broadly.