prometheus_get_cardinality
Identifies high series counts and label cardinality to troubleshoot Prometheus memory and query slowdowns.
Instructions
Get TSDB statistics and cardinality data from Prometheus.
Wraps GET /api/v1/status/tsdb. Returns head stats (total series,
chunks, time range) and top-N lists: metrics by series count, labels
by value count, and labels by memory usage.
Use this to investigate cardinality explosions — the #1 operational Prometheus problem. High series counts slow queries and increase memory.
Examples:
- Use when: "Why is Prometheus using so much memory?"
→ check num_series and top_metrics_by_series.
- Use when: "Which labels have the most values?"
→ check top_labels_by_value_count.
- Don't use when: You want current metric values
(call prometheus_query).
Returns:
dict with num_series / chunk_count / min_time / max_time /
top_metrics_by_series / top_labels_by_value_count /
top_labels_by_memory_bytes.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| instance | No |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| max_time | Yes | ||
| min_time | Yes | ||
| num_series | Yes | ||
| chunk_count | Yes | ||
| num_label_pairs | Yes | ||
| top_metrics_by_series | Yes | ||
| top_labels_by_value_count | Yes | ||
| top_labels_by_memory_bytes | Yes |