Loki is a horizontally-scalable, highly-available, multi-tenant, log aggregation system inspired by Prometheus. It is designed to be very cost effective, as it does not index the contents of the logs, but rather a set of labels for each log stream. Plain text logging with labels.
Almost all existing log aggregation solutions involve using full-text search systems to index logs (usually structured logs); at first glance this has some obvious advantages, with a rich and powerful feature set allowing for complex queries.