Merge branch 'background-migrations-system-load' into 'master'

Respond to DB health in background migrations

See merge request gitlab-org/gitlab-ce!20720

1 files changed, 31 insertions, 0 deletions

diff --git a/spec/models/postgresql/replication_slot_spec.rb b/spec/models/postgresql/replication_slot_spec.rb
new file mode 100644
index 00000000000..919a7526803
--- /dev/null
+++ b/spec/models/postgresql/replication_slot_spec.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Postgresql::ReplicationSlot, :postgresql do
+  describe '.lag_too_great?' do
+    it 'returns true when replication lag is too great' do
+      expect(described_class)
+        .to receive(:pluck)
+        .and_return([125.megabytes])
+
+      expect(described_class.lag_too_great?).to eq(true)
+    end
+
+    it 'returns false when more than one replicas is up to date enough' do
+      expect(described_class)
+        .to receive(:pluck)
+        .and_return([125.megabytes, 0.megabytes, 0.megabytes])
+
+      expect(described_class.lag_too_great?).to eq(false)
+    end
+
+    it 'returns false when replication lag is not too great' do
+      expect(described_class)
+        .to receive(:pluck)
+        .and_return([0.megabytes])
+
+      expect(described_class.lag_too_great?).to eq(false)
+    end
+  end
+end