info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
card "**Prometheus + Grafana**" as monitor #7FFFD4
package "GitLab Single Server" as gitlab-single-server {
together {
card "**GitLab Rails**" as gitlab #32CD32
card "**Gitaly**" as gitaly #FF8C00
card "**PostgreSQL**" as postgres #4EA7FF
card "**Redis**" as redis #FF6347
card "**Sidekiq**" as sidekiq #ff8dd1
}
card "Local Storage" as local_storage #white
}
gitlab -[#32CD32]--> gitaly
gitlab -[#32CD32]--> postgres
gitlab -[#32CD32]--> redis
gitlab -[#32CD32]--> sidekiq
gitaly -[#32CD32]--> local_storage
postgres -[#32CD32]--> local_storage
sidekiq -[#32CD32]--> local_storage
gitlab -[#32CD32]--> local_storage
monitor .[#7FFFD4]u-> gitlab
monitor .[#7FFFD4]u-> sidekiq
monitor .[#7FFFD4]-> postgres
monitor .[#7FFFD4]-> gitaly
monitor .[#7FFFD4,norank]--> redis
@enduml
```
The diagram above shows that while GitLab can be installed on a single server, it is internally composed of multiple services. As a GitLab instance is scaled, each of these services are broken out and independently scaled according to the demands placed on them. In some cases PaaS can be leveraged for some services (e.g. Cloud Object Storage for some file systems). For the sake of redundancy some of the services become clusters of nodes storing the same data. In a horizontal configuration of GitLab there are various ancillary services required to coordinate clusters or discover of resources (e.g. PgBouncer for Postgres connection management, Consul for Prometheus end point discovery).
## Requirements
Before starting, you should take note of the following requirements / guidance for this reference architecture.
### Supported CPUs
This reference architecture was built and tested on Google Cloud Platform (GCP) using the
As a general guidance, GitLab should run on most infrastructure such as reputable Cloud Providers (AWS, GCP, Azure) and their services, or self managed (ESXi) that meet both the specs detailed above, as well as any requirements in this section. However, this does not constitute a guarantee for every potential permutation.
Be aware of the following specific call outs:
- [Azure Database for PostgreSQL](https://docs.microsoft.com/en-us/azure/postgresql/#:~:text=Azure%20Database%20for%20PostgreSQL%20is,high%20availability%2C%20and%20dynamic%20scalability.) is [not recommended](https://gitlab.com/gitlab-org/quality/reference-architectures/-/issues/61) due to known performance issues or missing features.
- [Azure Blob Storage](https://docs.microsoft.com/en-us/azure/storage/blobs/) is recommended to be configured with [Premium accounts](https://docs.microsoft.com/en-us/azure/storage/blobs/storage-blob-block-blob-premium) to ensure consistent performance.
## Cloud Native Hybrid reference architecture with Helm Charts
Cloud Native Hybrid Reference Architecture is an alternative approach where select _stateless_
components are deployed in Kubernetes via our official [Helm Charts](https://docs.gitlab.com/charts/),
and _stateful_ components are deployed in compute VMs with Omnibus.
The [2k GitLab Cloud Native Hybrid](2k_users.md#cloud-native-hybrid-reference-architecture-with-helm-charts-alternative) (non HA) and [3k GitLab Cloud Native Hybrid](3k_users.md#cloud-native-hybrid-reference-architecture-with-helm-charts-alternative) (HA) reference architectures are the smallest we recommend in Kubernetes.
For environments that need to serve less users, you can lower the node specs. Depending on your user count, you can lower all suggested node specs as desired. However, it's recommended that you don't go lower than the [general requirements](../../install/requirements.md).
