Commit e8bcb974 authored by Thong Kuah's avatar Thong Kuah

Merge branch 'fix-db-recreate-for-db-cleaner' into 'master'

Fix `DbCleaner` migration helper to recreate DBs

See merge request gitlab-org/gitlab!70193
parents 179873ea b62f5796
......@@ -12,6 +12,13 @@ module Ci
if Gitlab::Database.has_config?(:ci)
connects_to database: { writing: :ci, reading: :ci }
# TODO: Load Balancing messes with `CiDatabaseRecord`
# returning wrong connection. To be removed once merged:
# https://gitlab.com/gitlab-org/gitlab/-/merge_requests/67773
def self.connection
retrieve_connection
end
end
end
end
......@@ -24,16 +24,6 @@ RSpec.describe Gitlab::Database::SchemaMigrations::Context do
end
context 'multiple databases', :reestablished_active_record_base do
let(:connection_class) do
Class.new(::ApplicationRecord) do
self.abstract_class = true
def self.name
'Gitlab::Database::SchemaMigrations::Context::TestConnection'
end
end
end
before do
connection_class.establish_connection(
ActiveRecord::Base
......@@ -44,10 +34,6 @@ RSpec.describe Gitlab::Database::SchemaMigrations::Context do
)
end
after do
connection_class.remove_connection
end
context 'when `schema_migrations_path` is configured as string' do
let(:configuration_overrides) do
{ "schema_migrations_path" => "db/ci_schema_migrations" }
......
......@@ -17,32 +17,9 @@ RSpec.configure do |config|
delete_from_all_tables!(except: ['work_item_types'])
# Postgres maximum number of columns in a table is 1600 (https://github.com/postgres/postgres/blob/de41869b64d57160f58852eab20a27f248188135/src/include/access/htup_details.h#L23-L47).
# And since:
# "The DROP COLUMN form does not physically remove the column, but simply makes
# it invisible to SQL operations. Subsequent insert and update operations in the
# table will store a null value for the column. Thus, dropping a column is quick
# but it will not immediately reduce the on-disk size of your table, as the space
# occupied by the dropped column is not reclaimed.
# The space will be reclaimed over time as existing rows are updated."
# according to https://www.postgresql.org/docs/current/sql-altertable.html.
# We drop and recreate the database if any table has more than 1200 columns, just to be safe.
max_allowed_columns = 1200
tables_with_more_than_allowed_columns =
ApplicationRecord.connection.execute("SELECT attrelid::regclass::text AS table, COUNT(*) AS column_count FROM pg_attribute GROUP BY attrelid HAVING COUNT(*) > #{max_allowed_columns}")
if tables_with_more_than_allowed_columns.any?
tables_with_more_than_allowed_columns.each do |result|
puts "The #{result['table']} table has #{result['column_count']} columns."
end
puts "Recreating the database"
start = Gitlab::Metrics::System.monotonic_time
ActiveRecord::Tasks::DatabaseTasks.drop_current
ActiveRecord::Tasks::DatabaseTasks.create_current
ActiveRecord::Tasks::DatabaseTasks.load_schema_current
ActiveRecord::Tasks::DatabaseTasks.migrate
puts "Database re-creation done in #{Gitlab::Metrics::System.monotonic_time - start}"
if any_connection_class_with_more_than_allowed_columns?
recreate_all_databases!
end
end
......
......@@ -2,7 +2,7 @@
module DbCleaner
def all_connection_classes
::ActiveRecord::Base.connection_handler.connection_pool_names.map(&:constantize)
::BeforeAllAdapter.all_connection_classes
end
def delete_from_all_tables!(except: [])
......@@ -20,6 +20,79 @@ module DbCleaner
DatabaseCleaner[:active_record, { connection: connection_class }]
end
end
def any_connection_class_with_more_than_allowed_columns?
all_connection_classes.any? do |connection_class|
more_than_allowed_columns?(connection_class)
end
end
def more_than_allowed_columns?(connection_class)
# Postgres maximum number of columns in a table is 1600 (https://github.com/postgres/postgres/blob/de41869b64d57160f58852eab20a27f248188135/src/include/access/htup_details.h#L23-L47).
# And since:
# "The DROP COLUMN form does not physically remove the column, but simply makes
# it invisible to SQL operations. Subsequent insert and update operations in the
# table will store a null value for the column. Thus, dropping a column is quick
# but it will not immediately reduce the on-disk size of your table, as the space
# occupied by the dropped column is not reclaimed.
# The space will be reclaimed over time as existing rows are updated."
# according to https://www.postgresql.org/docs/current/sql-altertable.html.
# We drop and recreate the database if any table has more than 1200 columns, just to be safe.
max_allowed_columns = 1200
tables_with_more_than_allowed_columns = connection_class.connection.execute(<<-SQL)
SELECT attrelid::regclass::text AS table, COUNT(*) AS column_count
FROM pg_attribute
GROUP BY attrelid
HAVING COUNT(*) > #{max_allowed_columns}
SQL
tables_with_more_than_allowed_columns.each do |result|
puts "The #{result['table']} (#{connection_class.connection_db_config.name}) table has #{result['column_count']} columns."
end
tables_with_more_than_allowed_columns.any?
end
def recreate_all_databases!
start = Gitlab::Metrics::System.monotonic_time
puts "Recreating the database"
force_disconnect_all_connections!
ActiveRecord::Tasks::DatabaseTasks.drop_current
ActiveRecord::Tasks::DatabaseTasks.create_current
ActiveRecord::Tasks::DatabaseTasks.load_schema_current
# Migrate each database individually
with_reestablished_active_record_base do
all_connection_classes.each do |connection_class|
ActiveRecord::Base.establish_connection(connection_class.connection_db_config)
ActiveRecord::Tasks::DatabaseTasks.migrate
end
end
puts "Databases re-creation done in #{Gitlab::Metrics::System.monotonic_time - start}"
end
def force_disconnect_all_connections!
all_connection_classes.each do |connection_class|
# We use `connection_pool` to avoid going through
# Load Balancer since it does retry ops
pool = connection_class.connection_pool
# Force disconnect https://www.cybertec-postgresql.com/en/terminating-database-connections-in-postgresql/
pool.connection.execute(<<-SQL)
SELECT pg_terminate_backend(pid)
FROM pg_stat_activity
WHERE datname = #{pool.connection.quote(pool.db_config.database)}
AND pid != pg_backend_pid();
SQL
connection_class.connection_pool.disconnect!
end
end
end
DbCleaner.prepend_mod_with('DbCleaner')
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