Technology: distributor
| ID | Title | Description | Category | Technology | Tags |
|---|---|---|---|---|---|
| prequel-2025-0098 Medium Impact: 6/10 Mitigation: 4/10 | Loki Pattern Ingester Empty Ring | Loki distributor encounters "empty ring" errors when attempting to send streams to pattern ingesters. This occurs when pattern ingestion is enabled in the configuration but no pattern-ingester pods are running or properly registered in the ring. The distributor's pattern-tee component cannot find any available pattern ingesters to process pattern extraction, leading to high error spam in logs while normal log ingestion continues to function. | Observability Problems | distributor | LokiConfigurationObservabilityDeploymentReplication |
| prequel-2025-0100 Medium Impact: 6/10 Mitigation: 4/10 | Prometheus ingestion failure due to too many labels | Grafana Mimir's distributor rejects incoming Prometheus series when the number of label names on a single series exceeds the configured per-tenant limit. When this occurs, logs contain the message "received a series whose number of labels exceeds the limit" and the affected samples are dropped. This typically arises from excessive or dynamic labeling in scrape targets or relabeling rules that generate many unique label names per series. To adjust the per-tenant limit, configure the distributor with `-validation.max-label-names-per-series`. When deploying via the `mimir-distributed` Helm chart, set `mimir.structuredConfig.limits.max_label_names_per_series` to a higher value (default is 30). Increase limits cautiously to avoid cardinality explosions and memory pressure. Prefer reducing label names at the source where possible. | Observability Problems | distributor | PrometheusGrafanaMetricsConfigurationConfiguration IssueThreshold ExceededObservability |