Remove outdated ci_setup.md doc page and document MySQL and RSpec profiling for specific branches

Signed-off-by: Rémy Coutable <[email protected]>

Author: rymai

.gitlab-ci.yml

@@ -59,7 +59,7 @@ stages:
 
 .only-master-and-ee-or-mysql: &only-master-and-ee-or-mysql
   only:
-    - /\-(?i)mysql$/
+    - /mysql/
     - master@gitlab-org/gitlab-ce
     - master@gitlab/gitlabhq
     - tags@gitlab-org/gitlab-ce

doc/development/README.md

@@ -33,7 +33,6 @@
 ## Backend howtos
 
 - [Architecture](architecture.md) of GitLab
-- [CI setup](ci_setup.md) for testing GitLab
 - [Gotchas](gotchas.md) to avoid
 - [How to dump production data to staging](db_dump.md)
 - [Instrumentation](instrumentation.md)

doc/development/ci_setup.md

@@ -448,13 +448,22 @@ is used for Spinach tests as well.
 
 ### Monitoring
 
-The GitLab test suite is [monitored] and a [public dashboard] is available for
-everyone to see. Feel free to look at the slowest test files and try to improve
-them.
+The GitLab test suite is [monitored] for the `master` branch, and any branch
+that includes `rspec-profile` in their name.
+
+A [public dashboard] is available for everyone to see. Feel free to look at the
+slowest test files and try to improve them.
 
 [monitored]: ./performance.md#rspec-profiling
 [public dashboard]: https://redash.gitlab.com/public/dashboards/l1WhHXaxrCWM5Ai9D7YDqHKehq6OU3bx5gssaiWe?org_slug=default
 
+## CI setup
+
+- On CE, the test suite only runs against PostgreSQL by default. We additionally
+  run the suite against MySQL for tags, `master`, and any branch that includes
+  `mysql` in the name.
+- On EE, the test suite always runs both PostgreSQL and MySQL.
+
 ## Spinach (feature) tests
 
 GitLab [moved from Cucumber to Spinach](https://github.com/gitlabhq/gitlabhq/pull/1426)