Geo Glossary (PREMIUM SELF)

NOTE: We are updating the Geo documentation, user interface and commands to reflect these changes. Not all pages comply with these definitions yet.

These are the defined terms to describe all aspects of Geo. Using a set of clearly defined terms helps us to communicate efficiently and avoids confusion. The language on this page aims to be ubiquitous and as simple as possible.

We provide example diagrams and statements to demonstrate correct usage of terms.

Term	Definition	Scope	Discouraged synonyms
Node	An individual server that runs GitLab either with a specific role or as a whole (for example a Rails application node). In a cloud context this can be a specific machine type.	GitLab	instance, server
Site	One or a collection of nodes running a single GitLab application. A site can be single-node or multi-node.	GitLab	deployment, installation instance
Single-node site	A specific configuration of GitLab that uses exactly one node.	GitLab	single-server, single-instance
Multi-node site	A specific configuration of GitLab that uses more than one node.	GitLab	multi-server, multi-instance, high availability
Primary site	A GitLab site whose data is being replicated by at least one secondary site. There can only be a single primary site.	Geo-specific	Geo deployment, Primary node
Secondary site	A GitLab site that is configured to replicate the data of a primary site. There can be one or more secondary sites.	Geo-specific	Geo deployment, Secondary node
Geo deployment	A collection of two or more GitLab sites with exactly one primary site being replicated by one or more secondary sites.	Geo-specific
Reference architecture	A specified configuration of GitLab for a number of users, possibly including multiple nodes and multiple sites.	GitLab
Promoting	Changing the role of a site from secondary to primary.	Geo-specific
Demoting	Changing the role of a site from primary to secondary.	Geo-specific
Failover	The entire process that shifts users from a primary Site to a secondary site. This includes promoting a secondary, but contains other parts as well. For example, scheduling maintenance.	Geo-specific
Replication	Also called "synchronization". The uni-directional process that updates a resource on a secondary site to match the resource on the primary site.	Geo-specific

Examples

Single-node site

 graph TD
   subgraph S-Site[Single-node site]
    Node_3[GitLab node]
  end

Multi-node site

 graph TD
   subgraph MN-Site[Multi-node site]
    Node_1[Application node]
    Node_2[Database node]
    Node_3[Gitaly node]
  end

Geo deployment - Single-node sites

This Geo deployment has a single-node primary site, a single-node secondary site:

 graph TD
   subgraph Geo deployment
   subgraph Primary[Primary site, single-node]
    Node_1[GitLab node]
  end
  subgraph Secondary1[Secondary site 1, single-node]
    Node_2[GitLab node]
   end
   end

Geo deployment - Multi-node sites

This Geo deployment has a multi-node primary site, a multi-node secondary site:

 graph TD
   subgraph Geo deployment
   subgraph Primary[Primary site, multi-node]
    Node_1[Application node]
    Node_2[Database node]
  end
  subgraph Secondary1[Secondary site 1, multi-node]
    Node_5[Application node]
    Node_6[Database node]
   end
   end

Geo deployment - Mixed sites

This Geo deployment has a multi-node primary site, a multi-node secondary site and another single-node secondary site:

 graph TD
   subgraph Geo deployment
   subgraph Primary[Primary site, multi-node]
    Node_1[Application node]
    Node_2[Database node]
    Node_3[Gitaly node]
  end
  subgraph Secondary1[Secondary site 1, multi-node]
    Node_5[Application node]
    Node_6[Database node]
   end
  subgraph Secondary2[Secondary site 2, single-node]
    Node_7[Single GitLab node]
   end
   end