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Diffstat (limited to 'doc/administration/geo/replication/high_availability.md')
| -rw-r--r-- | doc/administration/geo/replication/high_availability.md | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/doc/administration/geo/replication/high_availability.md b/doc/administration/geo/replication/high_availability.md index 5c124e9c6dc..8dd04cdace1 100644 --- a/doc/administration/geo/replication/high_availability.md +++ b/doc/administration/geo/replication/high_availability.md @@ -25,10 +25,17 @@ The **primary** and **secondary** Geo deployments must be able to communicate to ## Redis and PostgreSQL High Availability -The **primary** and **secondary** Redis and PostgreSQL should be configured -for high availability. Because of the additional complexity involved -in setting up this configuration for PostgreSQL and Redis, -it is not covered by this Geo HA documentation. +Geo supports: + +- Redis and PostgreSQL on the **primary** node configured for high availability +- Redis on **secondary** nodes configured for high availability. + +NOTE: **Note:** +Support for PostgreSQL on **secondary** nodes in high availability configuration +[is planned](https://gitlab.com/groups/gitlab-org/-/epics/2536). + +Because of the additional complexity involved in setting up this configuration +for PostgreSQL and Redis, it is not covered by this Geo HA documentation. For more information about setting up a highly available PostgreSQL cluster and Redis cluster using the omnibus package see the high availability documentation for [PostgreSQL](../../high_availability/database.md) and @@ -37,10 +44,17 @@ For more information about setting up a highly available PostgreSQL cluster and NOTE: **Note:** It is possible to use cloud hosted services for PostgreSQL and Redis, but this is beyond the scope of this document. -## Prerequisites: A working GitLab HA cluster +## Prerequisites: Two working GitLab HA clusters + +One cluster will serve as the **primary** node. Use the +[GitLab HA documentation](../../high_availability/README.md) to set this up. If +you already have a working GitLab instance that is in-use, it can be used as a +**primary**. -This cluster will serve as the **primary** node. Use the +The second cluster will serve as the **secondary** node. Again, use the [GitLab HA documentation](../../high_availability/README.md) to set this up. +It's a good idea to log in and test it, however, note that its data will be +wiped out as part of the process of replicating from the **primary**. ## Configure the GitLab cluster to be the **primary** node @@ -99,7 +113,11 @@ major differences: various resources. Therefore, we will set up the HA components one-by-one, and include deviations -from the normal HA setup. +from the normal HA setup. However, we highly recommend first configuring a +brand-new cluster as if it were not part of a Geo setup so that it can be +tested and verified as a working cluster. And only then should it be modified +for use as a Geo **secondary**. This helps to separate problems that are related +and are not related to Geo setup. ### Step 1: Configure the Redis and Gitaly services on the **secondary** node @@ -118,7 +136,8 @@ recommended. ### Step 2: Configure the main read-only replica PostgreSQL database on the **secondary** node NOTE: **Note:** The following documentation assumes the database will be run on -a single node only, rather than as a PostgreSQL cluster. +a single node only. PostgreSQL HA on **secondary** nodes is +[not currently supported](https://gitlab.com/groups/gitlab-org/-/epics/2536). Configure the [**secondary** database](database.md) as a read-only replica of the **primary** database. Use the following as a guide. @@ -167,6 +186,11 @@ the **primary** database. Use the following as a guide. ## the tracking database IP is in postgresql['md5_auth_cidr_addresses'] above. ## geo_postgresql['enable'] = false + + ## + ## Disable `geo_logcursor` service so Rails doesn't get configured here + ## + geo_logcursor['enable'] = false ``` After making these changes, [reconfigure GitLab][gitlab-reconfigure] so the changes take effect. @@ -335,6 +359,13 @@ On the secondary the following GitLab frontend services will be enabled: Verify these services by running `sudo gitlab-ctl status` on the frontend application servers. +You may wish to run backend application services on backend-specific servers. +For example, you can disable the `geo-logcursor` service with +`geo_logcursor['enable'] = false` and run it on application servers not +attached to the load balancer. On those backend application servers, you would +disable Unicorn with `unicorn['enable'] = false`. You might also choose to do +the same thing with the `sidekiq` service. + ### Step 5: Set up the LoadBalancer for the **secondary** node In this topology, a load balancer is required at each geographic location to |