**[Design document](https://gitlab.com/gitlab-org/gitaly/blob/master/doc/design_ha.md)** | This is the first checkpoint in shipping HA Gitaly https://gitlab.com/groups/gitlab-org/-/epics/842 ## Problem to solve Gitaly is currently a single point of failure. In order to make Gitaly highly available we will replicate Git repositories to multiple Gitaly nodes. ## Proposal In this first iteration, every Git write operation will trigger a complete sync from the primary to the replicas, followed by a verification to make sure each replica is an accurate copy of the primary. Based on the planned architecture, we will implement: - reverse-proxy **Praefect** that will manage replication - config based management - eventual consistency, no performance optimizations - monitoring to assess the replication delay of a naive implementation (we hope the delay will be around the 1 minute mark at 99p) This will allow small scale testing on GitLab.com by whitelisting a small number of projects to replicate.