Use the WAL Archiver Failures alert in Mini DBA to monitor PostgreSQL instances and make this condition visible before it becomes a wider database incident.
Mini DBA describes this alert as: WAL archiving failures can break point-in-time recovery and let WAL accumulate on disk. The default evaluation frequency is Minute, so the alert is intended to be close enough to operational reality for live triage.
This alert protects storage and recovery capacity. It helps you find growth, retention, and backup conditions that can stop writes, break recovery objectives, or leave the server without enough working space for normal database activity.
Enable it on systems with recovery objectives and on any database where a missed backup or archive problem would require business escalation. Test and lab systems can use looser settings if they are recreated from source control or seed data.
Threshold meaning: Failures per minute. Major threshold: 1 failures/min. Minor threshold: 0 failures/min. Comparison direction: "over". Use higher thresholds on batch-heavy, development, or intentionally bursty systems where brief pressure is expected. Use lower thresholds on latency-sensitive production systems, small instances with little headroom, and services with strict recovery or availability commitments.
Free space by removing safe-to-delete files, expanding the volume or tablespace, moving growth-heavy objects, correcting retention settings, or shrinking only after a documented one-off event. For recovery-related areas, verify that backups and log shipping or archiving are healthy before deleting anything.
Storage alerts should usually stay enabled even on quiet systems because the impact of missing them is high. Tune warning thresholds to leave enough time for approval, provisioning, and validation, especially when storage changes are handled by another infrastructure team.