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Cortex provides horizontally scalable, highly available, multi-tenant, long term storage for Prometheus.

  • Horizontally scalable: Cortex can run across multiple machines in a cluster, exceeding the throughput and storage of a single machine. This enables you to send the metrics from multiple Prometheus servers to a single Cortex cluster and run “globally aggregated” queries across all data in a single place.
  • Highly available: When run in a cluster, Cortex can replicate data between machines. This allows you to survive machine failure without gaps in your graphs.
  • Multi-tenant: Cortex can isolate data and queries from multiple different independent Prometheus sources in a single cluster, allowing untrusted parties to share the same cluster.
  • Long term storage: Cortex supports Amazon DynamoDB, Google Bigtable, Cassandra, S3 and GCS for long term storage of metric data. This allows you to durably store data for longer than the lifetime of any single machine, and use this data for long term capacity planning.

Cortex is a CNCF incubation project used in several production systems including Weave Cloud and Grafana Cloud. Cortex is primarily used as a remote write destination for Prometheus, exposing a Prometheus-compatible query API.


Read the getting started guide if you’re new to the project. Before deploying Cortex with a permanent storage backend you should read:

  1. An overview of Cortex’s architecture
  2. A guide to running Cortex
  3. Information regarding configuring Cortex

For a guide to contributing to Cortex, see the contributor guidelines.

Further reading

To learn more about Cortex, consult the following documents & talks:

Getting Help

If you have any questions about Cortex:

Your feedback is always welcome.

Hosted Cortex (Prometheus as a service)

There are several commercial services where you can use Cortex on-demand:

Weave Cloud

Weave Cloud from Weaveworks lets you deploy, manage, and monitor container-based applications. Sign up at and follow the instructions there. Additional help can also be found in the Weave Cloud documentation.

Instrumenting Your App: Best Practices

Grafana Cloud

To use Cortex as part of Grafana Cloud, sign up for Grafana Cloud by clicking “Log In” in the top right and then “Sign Up Now”. Cortex is included as part of the Starter and Basic Hosted Grafana plans.

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