Why we enabled Geo on the staging environment for GitLab.com

This post details the enablement of GitLab Geo on the staging environment for GitLab.com. It describes the motivation for testing Geo at scale, the setup process including selective synchronization of the 'gitlab-org' group, configuration of Gitaly shards, and the use of cascading streaming replication with Patroni. Challenges encountered include PostgreSQL 9.6 limitations with FDW queries and the need for increased statement timeouts. Bug fixes for synchronization issues were also identified and addressed. Future plans include enabling end-to-end tests on staging and testing high-availability configurations for PostgreSQL on Geo nodes.