Mimir
Overview
Mimir is the Prometheus-compatible backend receiving remote-write data from WxCDI Prometheus services and serving metric queries to Grafana.
Architecture
graph LR
P1["Prometheus DFW"] -->|"remote_write"| Ingest["Mimir Ingestion"]
P2["Prometheus SJC"] -->|"remote_write"| Ingest
Ingest --> Store["Metrics Storage"]
Store --> Query["Mimir Query Path"]
Query --> Grafana["Grafana"]
Query --> Rules["Alert Evaluation"]
Exact component topology and versions are owned by the shared metrics platform and current deployment configuration.
Configuration
Key integration settings include tenant/routing information, remote-write endpoint, queue behavior, authentication, and Grafana data-source configuration. Keep credentials in approved secret storage.
Prometheus and Grafana must use the same intended tenant. A healthy scrape with an empty Grafana query often indicates remote-write, tenant, data-source, or query-time-range mismatch rather than an exporter failure.
Maintenance
Monitor ingestion availability/rejections, remote-write backlog, query availability/latency, cardinality, storage, and compaction. Retention and storage policy values were not verified in the reviewed repositories; confirm them with the Mimir service owner.
Failure Isolation
| Observation | Likely boundary |
|---|---|
| Exporter and Prometheus are current; Mimir is stale | Prometheus remote-write queue, authentication, endpoint, or Mimir ingestion |
| Mimir query works; Grafana panel does not | Grafana data source, tenant header, variables, or panel query |
| Only one metric is rejected | Invalid sample, timestamp, label, or series limit |
| Queries degrade after a rollout | Cardinality growth, query shape, or backend capacity |
| One region is missing | Regional Prometheus remote write or region-specific configuration |
Operational Evidence
During an incident, capture:
- Prometheus scrape freshness and remote-write queue/failure metrics;
- Mimir ingestion errors or rejected-sample reason;
- tenant and data-source identity without secret headers;
- a bounded query showing the latest stored timestamp;
- affected region, jobs, and approximate series count;
- recovery time and whether backlogged samples arrived.
See Prometheus, Grafana, and Monitoring.