Cortex (monitoring)
Cortex is an open source, CNCF-hosted project that provides horizontally scalable, multi-tenant, long-term storage for Prometheus metrics, letting organizations run Prometheus-compatible monitoring as a shared service.
Definition
Cortex is an open source, CNCF-hosted project that provides horizontally scalable, multi-tenant, long-term storage for Prometheus metrics, letting organizations run Prometheus-compatible monitoring as a shared service.
Overview
Cortex was created to solve the same core problem Thanos addresses — single-server Prometheus doesn't scale well for long-term retention or multi-team, multi-tenant use — but with a different architectural approach built around a horizontally scalable set of microservices rather than layering on top of existing Prometheus instances. Cortex is designed to be run as a shared monitoring backend that multiple teams or tenants can write metrics into and query independently, with strict isolation between tenants' data. It remains compatible with the Prometheus query language (PromQL) and remote-write protocol, so existing Prometheus servers can send their data to Cortex without changing how teams already query and alert on metrics. The project is hosted by the Cloud Native Computing Foundation and shares design lineage with Grafana Labs' Mimir project, which forked from Cortex. Organizations typically choose between Cortex, Thanos, and VictoriaMetrics based on operational complexity trade-offs and existing infrastructure preferences, as all three solve overlapping long-term-storage and scale problems for Prometheus-style metrics.
Key Features
- Horizontally scalable, microservices-based architecture for metrics storage
- Multi-tenant isolation allowing multiple teams to share a single Cortex deployment
- Prometheus-compatible query language (PromQL) and remote-write ingestion
- Long-term metrics storage backed by object storage
- High availability designed for large-scale, multi-cluster metrics workloads
- CNCF-hosted open source project