Merge branch 'rnienaber-streaming-replication-8048' into 'master'

Logical replication is not supported for Geo

Closes #8048

See merge request gitlab-org/gitlab-ee!8132

doc/administration/geo/replication/database.md

@@ -49,6 +49,10 @@ The following guide assumes that:
   secondary's IP will be `5.6.7.8`. Note that the primary and secondary servers
   **must** be able to communicate over these addresses. More on this in the
   guide below.
+  
+CAUTION: **Warning:**
+Geo works with streaming replication. Logical replication is not supported at this time. 
+There is an [issue where support is being discussed](https://gitlab.com/gitlab-org/gitlab-ee/issues/7420).
 
 
 ### Step 1. Configure the primary server

doc/administration/geo/replication/database_source.md

@@ -43,6 +43,10 @@ The following guide assumes that:
   secondary's IP will be `5.6.7.8`. Note that the primary and secondary servers
   **must** be able to communicate over these addresses. These IP addresses can either
   be public or private.
+  
+CAUTION: **Warning:**
+Geo works with streaming replication. Logical replication is not supported at this time. 
+There is an [issue where support is being discussed](https://gitlab.com/gitlab-org/gitlab-ee/issues/7420).
 
 ### Step 1. Configure the primary server
 

doc/administration/geo/replication/faq.md

 # Geo Frequently Asked Questions
 
+## What are the minimum requirements to run Geo?
+
+The requirements are listed [on the index page](index.md#requirements-for-running-geo)
+
 ## Can I use Geo in a disaster recovery situation?
 
 Yes, but there are limitations to what we replicate (see

doc/administration/geo/replication/index.md

@@ -85,15 +85,17 @@ Note that the **secondary** node needs two different PostgreSQL databases:
 
 In the secondary nodes, there is an additional daemon: [Geo Log Cursor](#geo-log-cursor).
 
-## Geo Recommendations
+## Requirements for running Geo
 
-We highly recommend that you install Geo on an operating system that supports OpenSSH 6.9 or higher. The following operating systems are known to ship with a current version of OpenSSH:
+The following are required to run Geo:
 
-- [CentOS](https://www.centos.org) 7.4
-- [Ubuntu](https://www.ubuntu.com) 16.04
-
-NOTE: **Note:**
-CentOS 6 and 7.0 ship with an old version of OpenSSH that does not support [fast lookup of authorized SSH keys in the database](../../operations/fast_ssh_key_lookup.md), which Geo requires.
+- An operating system that supports OpenSSH 6.9+ (needed for
+  [fast lookup of authorized SSH keys in the database](../../operations/fast_ssh_key_lookup.md))
+  The following operating systems are known to ship with a current version of OpenSSH:
+    - [CentOS](https://www.centos.org) 7.4+
+    - [Ubuntu](https://www.ubuntu.com) 16.04+
+- PostgreSQL 9.6+ with [FDW](https://www.postgresql.org/docs/9.6/postgres-fdw.html) support and [Streaming Replication](https://wiki.postgresql.org/wiki/Streaming_Replication)
+- Git 2.9+
 
 ### Firewall rules
 
@@ -131,6 +133,7 @@ The tracking database instance is used as metadata to control what needs to be u
 - Fetch changes from a repository that has recently been updated.
 
 Because the replicated database instance is read-only, we need this additional database instance for each **secondary** node.
+The tracking database requires the `postgres_fdw` extension.
 
 ### Geo Log Cursor
 

doc/administration/geo/replication/security_review.md

@@ -116,7 +116,7 @@ over the public Internet in a typical deployment, but this is not a requirement.
 
 - Geo imposes no additional restrictions on operating system (see the
   [GitLab installation](https://about.gitlab.com/installation/) page for more
-  details), however we recommend using the operating systems listed in the [Geo documentation](http://docs.gitlab.com/ee/gitlab-geo/#geo-recommendations). 
+  details), however we recommend using the operating systems listed in the [Geo documentation](index.md#requirements-for-running-geo).
 
 ### What details regarding required OS components and lock‐down needs have been defined?