Instead of checking if a replica is online by just running "SELECT 1" we
instead check the replication status. If a replica is lagging behind too
much time and data wise we'll stop using it until it is back in sync
with the primary. We also only check for the status roughly every 30
seconds. This reduces the overhead of the status checks, at the cost of
the status potentially lagging behind the real world for 30 seconds or
so.

Checking the replicas happens in a request, without any central
coordination mechanism. This keeps the implementation simple and the
processes independent of _another_ central service. To prevent all
processes from doing the same work at the same time we randomize the
checking intervals on a per process basis. This won't prevent 2
processes from checking at the same time, but it does reduce the
likelihood of _all_ of check checking at the same time.

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/2197, closes
https://gitlab.com/gitlab-org/gitlab-ee/issues/2866

Merge branch 'ee-38962-automatically-run-a-pipeline-when-auto-devops-is-turned-on-in-project-settings' into 'master'

Add checkbox to automatically run a pipeline when Auto DevOps is turned on in project settings -- EE merge edition

Closes gitlab-ce#38962

See merge request gitlab-org/gitlab-ee!3578

Fix viewing default push rules on a Geo secondary

Closes #4110

See merge request gitlab-org/gitlab-ee!3559

Port of CE branch '21143-customize-branch-name-when-using-create-branch-in-an-issue '

See merge request gitlab-org/gitlab-ee!3554

Add border for epic edit button

Closes #3909

See merge request gitlab-org/gitlab-ee!3506

Fix tasklist for epics

Closes #4021

See merge request gitlab-org/gitlab-ee!3435

[EE] Add timeouts for Gitaly calls

See merge request gitlab-org/gitlab-ee!3541

CE upstream

Closes omnibus-gitlab#2988 et gitlab-com/infrastructure#3260

See merge request gitlab-org/gitlab-ee!3570

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/38962

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/38962

Conflicts:
	app/services/projects/update_service.rb
	spec/services/projects/update_service_spec.rb

Add feature flag to use gitaly-ssh mirroring when cloning internal repos

Closes gitaly#739

See merge request gitlab-org/gitlab-ee!3479

Add a section on Connection flows

Closes gitlab-org/build/team-tasks#28

See merge request gitlab-org/gitlab-ee!3562

Geo - Does not sync repos on unhealthy shards in non-backfill conditions

Closes #3690

See merge request gitlab-org/gitlab-ee!3540

As part of the architecture, say what ports are used by what services
when.  This should add value in debugging data flows, and opening
firewalls.

Fix wiki retry count typo

Closes #4177

See merge request gitlab-org/gitlab-ee!3569

[EE] Hashed Storage Attachments migration path

See merge request gitlab-org/gitlab-ee!3544

[EE] Strip leading & trailing whitespaces in CI/CD secret variable keys, and environment scope

Closes gitlab-ce#40561

See merge request gitlab-org/gitlab-ee!3563