Merge branch 'yorick/fix-primary-host-release' into 'master'

Don't release primary connections in the DB LB

See merge request gitlab-org/gitlab!69988

lib/gitlab/database/load_balancing/host.rb

@@ -163,8 +163,6 @@ module Gitlab
 
         def primary_write_location
           load_balancer.primary_write_location
-        ensure
-          load_balancer.release_primary_connection
         end
 
         def database_replica_location

lib/gitlab/database/load_balancing/primary_host.rb

@@ -16,7 +16,8 @@ module Gitlab
         end
 
         def release_connection
-          @load_balancer.release_primary_connection
+          # no-op as releasing primary connections isn't needed.
+          nil
         end
 
         def enable_query_cache!
@@ -51,8 +52,6 @@ module Gitlab
 
         def primary_write_location
           @load_balancer.primary_write_location
-        ensure
-          @load_balancer.release_primary_connection
         end
 
         def database_replica_location

spec/lib/gitlab/database/load_balancing/primary_host_spec.rb

@@ -20,10 +20,8 @@ RSpec.describe Gitlab::Database::LoadBalancing::PrimaryHost do
   end
 
   describe '#release_connection' do
-    it 'releases a connection from the pool' do
-      expect(load_balancer).to receive(:release_primary_connection)
-
-      host.release_connection
+    it 'does nothing' do
+      expect(host.release_connection).to be_nil
     end
   end