High Availability

GitLab supports several different types of clustering and high-availability. The solution you choose will be based on the level of scalability and availability you require. The easiest solutions are scalable, but not necessarily highly available.

Architecture

Active/Passive

For pure high-availability/failover with no scaling you can use an active/passive configuration. This utilizes DRBD (Distributed Replicated Block Device) to keep all data in sync. DRBD requires a low latency link to remain in sync. It is not advisable to attempt to run DRBD between data centers or in different cloud availability zones.

Components/Servers Required:

  • 2 servers/virtual machines (one active/one passive)

Active/Passive HA Diagram

Active/Active

This architecture scales easily because all application servers handle user requests simultaneously. The database, Redis, and GitLab application are all deployed on separate servers. The configuration is only highly-available if the database, Redis and storage are also configured as such.

Active/Active HA Diagram

Steps to configure active/active:

  1. Configure the database
  2. Configure Redis
  3. Configure NFS
  4. Configure the GitLab application servers
  5. Configure the load balancers