# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""
SQLAlchemy database backend
"""
import time

from sqlalchemy.exc import OperationalError

from nova import flags
from nova import log as logging
from nova.db.sqlalchemy import models


FLAGS = flags.FLAGS
LOG = logging.getLogger('nova.db.sqlalchemy')


for i in xrange(FLAGS.sql_max_retries):
    if i > 0:
        time.sleep(FLAGS.sql_retry_interval)

    try:
        models.register_models()
        break
    except OperationalError:
        LOG.exception(_("Data store %s is unreachable."
                        " Trying again in %d seconds."),
                      FLAGS.sql_connection, FLAGS.sql_retry_interval)
