def acquire(self): basedir = os.path.dirname(self.fname) if not os.path.exists(basedir): fileutils.ensure_tree(basedir) LOG.info(_LI('Created lock path: %s'), basedir) self.lockfile = open(self.fname, 'w') while True: try: # Using non-blocking locks since green threads are not # patched to deal with blocking locking calls. # Also upon reading the MSDN docs for locking(), it seems # to have a laughable 10 attempts "blocking" mechanism. self.trylock() LOG.debug('Got file lock "%s"', self.fname) return True except IOError as e: if e.errno in (errno.EACCES, errno.EAGAIN): # external locks synchronise things like iptables # updates - give it some time to prevent busy spinning time.sleep(0.01) else: raise threading.ThreadError(_("Unable to acquire lock on" " `%(filename)s` due to" " %(exception)s") % { 'filename': self.fname, 'exception': e, })
def acquire(self): basedir = os.path.dirname(self.fname) if not os.path.exists(basedir): fileutils.ensure_tree(basedir) LOG.info(_LI('Created lock path: %s'), basedir) self.lockfile = open(self.fname, 'w') while True: try: # Using non-blocking locks since green threads are not # patched to deal with blocking locking calls. # Also upon reading the MSDN docs for locking(), it seems # to have a laughable 10 attempts "blocking" mechanism. self.trylock() LOG.debug('Got file lock "%s"', self.fname) return True except IOError as e: if e.errno in (errno.EACCES, errno.EAGAIN): # external locks synchronise things like iptables # updates - give it some time to prevent busy spinning time.sleep(0.01) else: raise threading.ThreadError( _("Unable to acquire lock on" " `%(filename)s` due to" " %(exception)s") % { 'filename': self.fname, 'exception': e, })
def remove_external_lock_file(name, lock_file_prefix=None): """Remove a external lock file when it's not used anymore This will be helpful when we have a lot of lock files """ with internal_lock(name): lock_file_path = _get_lock_path(name, lock_file_prefix) try: os.remove(lock_file_path) except OSError: LOG.info(_LI('Failed to remove file %(file)s'), {'file': lock_file_path})
def drop_old_duplicate_entries_from_table(migrate_engine, table_name, use_soft_delete, *uc_column_names): """Drop all old rows having the same values for columns in uc_columns. This method drop (or mark ad `deleted` if use_soft_delete is True) old duplicate rows form table with name `table_name`. :param migrate_engine: Sqlalchemy engine :param table_name: Table with duplicates :param use_soft_delete: If True - values will be marked as `deleted`, if False - values will be removed from table :param uc_column_names: Unique constraint columns """ meta = MetaData() meta.bind = migrate_engine table = Table(table_name, meta, autoload=True) columns_for_group_by = [table.c[name] for name in uc_column_names] columns_for_select = [func.max(table.c.id)] columns_for_select.extend(columns_for_group_by) duplicated_rows_select = select(columns_for_select, group_by=columns_for_group_by, having=func.count(table.c.id) > 1) for row in migrate_engine.execute(duplicated_rows_select): # NOTE(boris-42): Do not remove row that has the biggest ID. delete_condition = table.c.id != row[0] is_none = None # workaround for pyflakes delete_condition &= table.c.deleted_at == is_none for name in uc_column_names: delete_condition &= table.c[name] == row[name] rows_to_delete_select = select([table.c.id]).where(delete_condition) for row in migrate_engine.execute(rows_to_delete_select).fetchall(): LOG.info( _LI("Deleting duplicated row with id: %(id)s from table: " "%(table)s") % dict(id=row[0], table=table_name)) if use_soft_delete: delete_statement = table.update().\ where(delete_condition).\ values({ 'deleted': literal_column('id'), 'updated_at': literal_column('updated_at'), 'deleted_at': timeutils.utcnow() }) else: delete_statement = table.delete().where(delete_condition) migrate_engine.execute(delete_statement)
def drop_old_duplicate_entries_from_table(migrate_engine, table_name, use_soft_delete, *uc_column_names): """Drop all old rows having the same values for columns in uc_columns. This method drop (or mark ad `deleted` if use_soft_delete is True) old duplicate rows form table with name `table_name`. :param migrate_engine: Sqlalchemy engine :param table_name: Table with duplicates :param use_soft_delete: If True - values will be marked as `deleted`, if False - values will be removed from table :param uc_column_names: Unique constraint columns """ meta = MetaData() meta.bind = migrate_engine table = Table(table_name, meta, autoload=True) columns_for_group_by = [table.c[name] for name in uc_column_names] columns_for_select = [func.max(table.c.id)] columns_for_select.extend(columns_for_group_by) duplicated_rows_select = select(columns_for_select, group_by=columns_for_group_by, having=func.count(table.c.id) > 1) for row in migrate_engine.execute(duplicated_rows_select): # NOTE(boris-42): Do not remove row that has the biggest ID. delete_condition = table.c.id != row[0] is_none = None # workaround for pyflakes delete_condition &= table.c.deleted_at == is_none for name in uc_column_names: delete_condition &= table.c[name] == row[name] rows_to_delete_select = select([table.c.id]).where(delete_condition) for row in migrate_engine.execute(rows_to_delete_select).fetchall(): LOG.info(_LI("Deleting duplicated row with id: %(id)s from table: " "%(table)s") % dict(id=row[0], table=table_name)) if use_soft_delete: delete_statement = table.update().\ where(delete_condition).\ values({ 'deleted': literal_column('id'), 'updated_at': literal_column('updated_at'), 'deleted_at': timeutils.utcnow() }) else: delete_statement = table.delete().where(delete_condition) migrate_engine.execute(delete_statement)