Open source, horizontally scalable, multi-tenant Prometheus as a service

Cortex is a CNCF sandbox project used in several production systems including Weave Cloud, GrafanaCloud and FreshTracks.io.

Cortex provides horizontally scalable, multi-tenant, long term storage for Prometheus metrics when used as a remote write destination, and a horizontally scalable, Prometheus-compatible query API.

Multi-tenant means it handles metrics from multiple independent Prometheus sources, keeping them separate.

Instrumenting Your App: Best Practices

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 https://cloud.weave.works and follow the instructions there. Additional help can also be found in the Weave Cloud documentation.

GrafanaCloud

To use Cortex as part of Grafana Cloud, sign up for GrafanaCloud 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.

Contributing

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

For Developers

To build:

make

(By default, the build runs in a Docker container, using an image built with all the tools required. The source code is mounted from where you run make into the build container as a Docker volume.)

To run the test suite:

make test

Playing in minikube

First, start minikube.

You may need to load the Docker images into your minikube environment. There is a convenience rule in the Makefile to do this:

make prime-minikube

Then run Cortex in minikube:

kubectl apply -f ./k8s

(these manifests use latest tags, i.e. this will work if you have just built the images and they are available on the node(s) in your Kubernetes cluster)

Cortex will sit behind an nginx instance exposed on port 30080. A job is deployed to scrape itself. Try it:

http://192.168.99.100:30080/api/prom/api/v1/query?query=up

If that doesn't work, your Minikube might be using a different ip address. Check with minikube status.

Vendoring

We use dep to vendor dependencies. To fetch a new dependency, run:

dep ensure

To update dependencies, run

dep ensure -update

Further reading

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

• Original design document for Project Frankenstein
• PromCon 2016 Talk: "Project Frankenstein: Multitenant, Scale-Out Prometheus": video, slides
• KubeCon Prometheus Day talk "Weave Cortex: Multi-tenant, horizontally scalable Prometheus as a Service" slides
• CNCF TOC Presentation; "Horizontally Scalable, Multi-tenant Prometheus" slides

Getting Help

If you have any questions about Cortex:

• Ask a question on the Cortex Slack channel. To invite yourself to the CNCF Slack, visit http://slack.cncf.io/.
• File an issue.
• Send an email to cortex-users@lists.cncf.io

Your feedback is always welcome.