Use Gitlab::Database.with_connection_pool from !9192

db/post_migrate/20170206040400_remove_inactive_default_email_services.rb

@@ -6,53 +6,36 @@ class RemoveInactiveDefaultEmailServices < ActiveRecord::Migration
   disable_ddl_transaction!
 
   def up
-    pool = create_connection_pool
-    threads = []
-
-    threads << Thread.new do
-      pool.with_connection do |connection|
-        connection.execute <<-SQL.strip_heredoc
-        DELETE FROM services
-          WHERE type = 'BuildsEmailService'
-            AND active IS FALSE
-            AND properties = '{"notify_only_broken_builds":true}';
-        SQL
+    Gitlab::Database.with_connection_pool(2) do |pool|
+      threads = []
+
+      threads << Thread.new do
+        pool.with_connection do |connection|
+          connection.execute <<-SQL.strip_heredoc
+          DELETE FROM services
+            WHERE type = 'BuildsEmailService'
+              AND active IS FALSE
+              AND properties = '{"notify_only_broken_builds":true}';
+          SQL
+        end
       end
-    end
 
-    threads << Thread.new do
-      pool.with_connection do |connection|
-        connection.execute <<-SQL.strip_heredoc
-        DELETE FROM services
-          WHERE type = 'PipelinesEmailService'
-            AND active IS FALSE
-            AND properties = '{"notify_only_broken_pipelines":true}';
-        SQL
+      threads << Thread.new do
+        pool.with_connection do |connection|
+          connection.execute <<-SQL.strip_heredoc
+          DELETE FROM services
+            WHERE type = 'PipelinesEmailService'
+              AND active IS FALSE
+              AND properties = '{"notify_only_broken_pipelines":true}';
+          SQL
+        end
       end
-    end
 
-    threads.each(&:join)
-    pool.disconnect!
+      threads.each(&:join)
+    end
   end
 
   def down
     # Nothing can be done to restore the records
   end
-
-  private
-
-  def create_connection_pool
-    # See activerecord-4.2.7.1/lib/active_record/connection_adapters/connection_specification.rb
-    env = Rails.env
-    original_config = ActiveRecord::Base.configurations
-    env_config = original_config[env].merge('pool' => 2)
-    config = original_config.merge(env => env_config)
-
-    spec =
-      ActiveRecord::
-        ConnectionAdapters::
-        ConnectionSpecification::Resolver.new(config).spec(env.to_sym)
-
-    ActiveRecord::ConnectionAdapters::ConnectionPool.new(spec)
-  end
 end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170204181513) do
+ActiveRecord::Schema.define(version: 20170210075922) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"