Merge branch 'docs-10k-ref-wip' into 'master'

Add the 10k ref architecture specs to HA docs

See merge request gitlab-org/gitlab-ce!28149

doc/administration/high_availability/README.md

@@ -145,14 +145,38 @@ environments this is a good architecture to consider if you foresee or do have
 contention due to certain workloads.
 
 - 3 PostgreSQL nodes
+- 1 PgBouncer node
 - 2 Redis nodes
 - 3 Consul/Sentinel nodes
 - 2 or more Sidekiq nodes
-- 2 or more Web nodes (Unicorn, Workhorse, PGBouncer)
+- 2 or more GitLab application nodes (Unicorn, Workhorse)
 - 1 or more NFS/Gitaly servers
+- 1 Monitoring node (Prometheus, Grafana)
 
 ![Hybrid architecture diagram](https://docs.gitlab.com/ee/administration/img/high_availability/hybrid.png)
 
+#### Reference Architecture
+
+- **Status:** Work-in-progress
+- **Supported Users (approximate):** 10,000
+- **Related Issues:** [gitlab-com/support/support-team-meta#1513](https://gitlab.com/gitlab-com/support/support-team-meta/issues/1513), 
+ [gitlab-org/quality/team-tasks#110](https://gitlab.com/gitlab-org/quality/team-tasks/issues/110)
+
+The Support and Quality teams are in the process of building and performance testing
+an environment that will support about 10,000 users. The specifications below
+are a work-in-progress representation of the work so far. Quality will be 
+certifying this environment in FY20-Q2. The specifications may be adjusted 
+prior to certification based on performance testing. 
+
+- 3 PostgreSQL - 4 CPU, 8GB RAM
+- 1 PgBouncer - 2 CPU, 4GB RAM
+- 2 Redis - 2 CPU, 8GB RAM
+- 3 Consul/Sentinel - 2 CPU, 2GB RAM
+- 4 Sidekiq - 4 CPU, 8GB RAM
+- 5 GitLab application nodes - 20 CPU, 64GB RAM
+- 1 Gitaly - 20 CPU, 64GB RAM
+- 1 Monitoring node - 4 CPU, 8GB RAM
+
 ### Fully Distributed
 
 This architecture scales to hundreds of thousands of users and projects and is