Prometheus on a Small VPS: What to Scrape Without Blowing RAM

Prometheus on a Small VPS: What to Scrape Without Blowing RAM

Prometheus is powerful, but default enthusiasm often over-scrapes small environments. On tiny VPS plans, monitoring can become the resource problem it is supposed to prevent.

Minimum viable scrape set

Start with:

• host metrics (CPU, memory, disk, network)
• app-level request/error/latency metrics
• database health and connection pressure
• queue depth and worker lag (if used)

Skip low-value high-cardinality metrics until you prove need.

Cardinality discipline

Biggest RAM killers:

• unbounded labels (user ID, request ID, session tokens)
• excessive per-endpoint labels without aggregation strategy

Control label design early. Retrofitting later is painful.

Retention and scrape interval tuning

• use sensible retention for incident and trend needs
• increase scrape interval on low-volatility metrics
• isolate high-frequency metrics to critical services only

Reference

• Prometheus docs and concepts: prometheus.io/docs

Final takeaway

Small VPS monitoring should optimize for decision quality, not metric quantity. A focused scrape profile gives better reliability outcomes at lower operational cost.