# Cortex: A Multi-Tenant, Horizontally Scalable Prometheus-as-a-Service | Cloud Native Computing Foundation ![rw-book-cover](https://www.cncf.io/wp-content/uploads/2020/08/Cortex-blog-post-2.png) URL:: https://www.cncf.io/blog/2018/12/18/cortex-a-multi-tenant-horizontally-scalable-prometheus-as-a-service/ Author:: Luc Perkins ## Highlights > Prometheus quickly garnered widespread adoption and later became one of the first CNCF projects and just the second to graduate (after [Kubernetes](https://kubernetes.io/)). It’s used by tons of forward-thinking companies in production, including heavyweights like [DigitalOcean](https://digitalocean.com/), [Fastly](https://fastly.com/), and [Weaveworks](https://www.weave.works/), and has its own dedicated yearly conference, [PromCon](https://promcon.io/). ([View Highlight](https://read.readwise.io/read/01fdawkqy2dgaajra2s1t2w1np)) > Prometheus does *not*, however, provide some of the capabilities that you’d expect from a full-fledged “as-a-Service” platform, such as multi-tenancy, authentication and authorization, and built-in long-term storage. ([View Highlight](https://read.readwise.io/read/01fdawmxgdgqm03mc9zw99fy41)) > [Cortex](https://github.com/cortexproject/cortex), which [joined the CNCF](https://www.cncf.io/blog/2018/09/20/cncf-to-host-cortex-in-the-sandbox/) in September as a sandbox project, is an open-source Prometheus-as-a-Service platform that seeks to fill those gaps and to thereby provide a complete, secure, multi-tenant Prometheus experience. ([View Highlight](https://read.readwise.io/read/01fdawn576yfzvvyew58r1scnc)) > • Prometheus offers a simple and easily adoptable [metrics exposition format](https://prometheus.io/docs/instrumenting/writing_exporters/) that makes it easy to write your own metrics exporters. This format is even being turned into an open standard via the [OpenMetrics](https://openmetrics.io/) project (which also recently joined the [CNCF sandbox](https://landscape.cncf.io/cncf=sandbox)). > • Prometheus offers a simple but powerful label-based querying language, [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/), for working with time series data. I find PromQL to be highly intuitive ([View Highlight](https://read.readwise.io/read/01fdawnpe5k1y2hhc0j1v6rj9j)) > **Long-term storage** – Individual Prometheus instances provide durable storage of time series data, but they do *not* act as a distributed data storage system with features like cross-node replication and automatic repair. This means that durability guarantees are restricted to that of a single machine. Fortunately, Prometheus offers a [remote write API](https://prometheus.io/docs/prometheus/latest/storage/#remote-storage-integrations) that can be used to pipe time series data to other systems. ([View Highlight](https://read.readwise.io/read/01fdaxrq5hhwmkp0j63v4yh17y)) > Multi-tenancy is woven into the very fabric of Cortex. *All* time series data that arrives in Cortex from Prometheus instances is marked as belonging to a specific tenant in the request metadata. From there, that data can only be queried by the same tenant. Alerting is multi-tenant as well, with each tenant able to configure its own alerts using [Alertmanager configuration](https://prometheus.io/docs/alerting/configuration/). ([View Highlight](https://read.readwise.io/read/01fdaxr57saj2730b3bzs2gb4f)) > With the addition of Cortex to the CNCF sandbox, there are now three Prometheus-related projects under the CNCF umbrella (including [Prometheus](https://prometheus.io) itself and [OpenMetrics](https://openmetrics.io)). ([View Highlight](https://read.readwise.io/read/01fdaxqhz6qbby8wg5sqerkk5j)) --- Title: Cortex: A Multi-Tenant, Horizontally Scalable Prometheus-as-a-Service | Cloud Native Computing Foundation Author: Luc Perkins Tags: readwise, articles date: 2024-01-30 --- # Cortex: A Multi-Tenant, Horizontally Scalable Prometheus-as-a-Service | Cloud Native Computing Foundation ![rw-book-cover](https://www.cncf.io/wp-content/uploads/2020/08/Cortex-blog-post-2.png) URL:: https://www.cncf.io/blog/2018/12/18/cortex-a-multi-tenant-horizontally-scalable-prometheus-as-a-service/ Author:: Luc Perkins ## AI-Generated Summary Prometheus is one of the standard-bearing open-source solutions for monitoring and observability. From its humble origins at SoundCloud in 2012, Prometheus quickly garnered widespread adoption and… ## Highlights > Prometheus quickly garnered widespread adoption and later became one of the first CNCF projects and just the second to graduate (after [Kubernetes](https://kubernetes.io/)). It’s used by tons of forward-thinking companies in production, including heavyweights like [DigitalOcean](https://digitalocean.com/), [Fastly](https://fastly.com/), and [Weaveworks](https://www.weave.works/), and has its own dedicated yearly conference, [PromCon](https://promcon.io/). ([View Highlight](https://read.readwise.io/read/01fdawkqy2dgaajra2s1t2w1np)) > Prometheus does *not*, however, provide some of the capabilities that you’d expect from a full-fledged “as-a-Service” platform, such as multi-tenancy, authentication and authorization, and built-in long-term storage. ([View Highlight](https://read.readwise.io/read/01fdawmxgdgqm03mc9zw99fy41)) > [Cortex](https://github.com/cortexproject/cortex), which [joined the CNCF](https://www.cncf.io/blog/2018/09/20/cncf-to-host-cortex-in-the-sandbox/) in September as a sandbox project, is an open-source Prometheus-as-a-Service platform that seeks to fill those gaps and to thereby provide a complete, secure, multi-tenant Prometheus experience. ([View Highlight](https://read.readwise.io/read/01fdawn576yfzvvyew58r1scnc)) > • Prometheus offers a simple and easily adoptable [metrics exposition format](https://prometheus.io/docs/instrumenting/writing_exporters/) that makes it easy to write your own metrics exporters. This format is even being turned into an open standard via the [OpenMetrics](https://openmetrics.io/) project (which also recently joined the [CNCF sandbox](https://landscape.cncf.io/cncf=sandbox)). > • Prometheus offers a simple but powerful label-based querying language, [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/), for working with time series data. I find PromQL to be highly intuitive ([View Highlight](https://read.readwise.io/read/01fdawnpe5k1y2hhc0j1v6rj9j)) > **Long-term storage** – Individual Prometheus instances provide durable storage of time series data, but they do *not* act as a distributed data storage system with features like cross-node replication and automatic repair. This means that durability guarantees are restricted to that of a single machine. Fortunately, Prometheus offers a [remote write API](https://prometheus.io/docs/prometheus/latest/storage/#remote-storage-integrations) that can be used to pipe time series data to other systems. ([View Highlight](https://read.readwise.io/read/01fdaxrq5hhwmkp0j63v4yh17y)) > Multi-tenancy is woven into the very fabric of Cortex. *All* time series data that arrives in Cortex from Prometheus instances is marked as belonging to a specific tenant in the request metadata. From there, that data can only be queried by the same tenant. Alerting is multi-tenant as well, with each tenant able to configure its own alerts using [Alertmanager configuration](https://prometheus.io/docs/alerting/configuration/). ([View Highlight](https://read.readwise.io/read/01fdaxr57saj2730b3bzs2gb4f)) > With the addition of Cortex to the CNCF sandbox, there are now three Prometheus-related projects under the CNCF umbrella (including [Prometheus](https://prometheus.io) itself and [OpenMetrics](https://openmetrics.io)). ([View Highlight](https://read.readwise.io/read/01fdaxqhz6qbby8wg5sqerkk5j))