Loki is a horizontally scalable, multi-tenant log aggregation system created by Grafana Labs. It is designed for efficient and cost-effective log storage and retrieval and is often used alongside Grafana for visualization.

Loki's Key Features

• Index-Free Logging: Unlike traditional logging systems like Elasticsearch, Loki does not index the contents of logs. Instead, it indexes only the metadata (labels), making it much cheaper and faster for ingestion.
• Label-Based Log Searching: Logs are identified using labels (like job, instance, namespace), making queries efficient without the complexity of full-text indexing.
• Integration with Prometheus: Loki follows a design philosophy similar to Prometheus, using labels and supporting queries via LogQL (similar to PromQL for metrics).
• Efficient Storage: Loki compresses logs and stores them in chunks, often using object storage like S3, GCS, or Azure Blob Storage to reduce costs.
• Multi-Tenant & Scalable: Loki supports multi-tenancy and horizontally scales, meaning it can handle large volumes of logs across distributed systems.

Guides

• Setup Loki with an open telemetry collector
• Add Loki as a Grafana Data Source