What to monitor
On This Lesson 4 topics
This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.
In this lesson
know the key database health indicators.
Planned topics
- Connections: used vs
max_connections; idle in transaction count. - Locks and long-running queries (
pg_stat_activity,pg_locks). - Cache hit ratio from
pg_stat_database(blks_hit vs blks_read); low means too little memory or bad queries. - Replication lag (bytes and seconds) and archive success.
- Disk free space and WAL directory growth; dead tuples and autovacuum activity.
Draft outline details
Demonstration
a dashboard sketch with six panels and an alert threshold for each; mention postgres_exporter with Prometheus (verify choice before recording).
Check your understanding
Which indicator warns you that WAL is piling up before the disk fills?
Show answer
Disk or WAL directory growth, often from a stuck archive or lagging replica slot.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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