Grafana Loki

Loki is a horizontally scalable, multi-tenant log aggregation system built by Grafana Labs and described by its own maintainers as "like Prometheus, but for logs." Instead of doing full-text indexing on log content, it indexes only a set of labels attached to each log stream, which keeps it simpler to operate and cheaper to run than log systems that index every word.

Because it uses the same label model as Prometheus, teams already using Prometheus-style labels can query and correlate metrics and logs using consistent labels rather than maintaining two separate labeling schemes, and Loki has native support in Grafana for visualizing that correlated data. It's also a strong fit for Kubernetes environments specifically, since Pod metadata like labels is scraped and indexed automatically.

Loki is a fit for teams that already use Prometheus and Grafana for metrics and want a log-aggregation system that follows the same operational model, rather than adopting a separate, differently-architected logging stack.