Stats API

S4 provides a lightweight JSON stats endpoint designed for dashboard widgets and quick health checks.

Endpoint

GET /api/stats

curl http://localhost:9000/api/stats

No authentication required.

Response

{
  "uptime_seconds": 86400,
  "buckets_count": 5,
  "objects_count": 12345,
  "storage_used_bytes": 1073741824,
  "dedup_unique_blobs": 8000,
  "dedup_total_references": 12345,
  "dedup_ratio": 0.352,
  "complete": true
}

Fields

On a cluster node

buckets_count, objects_count and storage_used_bytes are the pool's, whichever node is asked: buckets and objects are listed from every node of the pool and merged by key, so an object counts once, at the size of its newest version. Counting the pool lists every object in it, so a node reuses the count for up to 10 seconds and computes it once for all the requests that arrive meanwhile; creating or deleting a bucket through the node counts again at once. The deduplication fields stay the node's own: each node deduplicates what it stores.

Use Cases

• Web Console Dashboard — the S4 Console uses this endpoint for its dashboard widgets
• Health Checks — use /health instead: it answers at once, while this endpoint counts every object (on a cluster node, of the whole pool)
• Custom Dashboards — build your own monitoring UI using this JSON data
• Alerts — trigger alerts based on storage usage or object counts

Difference from /metrics