trove/trove/guestagent/strategies/replication/mysql_binlog.py

80 lines
3.1 KiB
Python

# Copyright 2014 Tesora, Inc.
# 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.
#
import csv
from oslo_log import log as logging
from trove.common import exception
from trove.common.i18n import _
from trove.guestagent.backup.backupagent import BackupAgent
from trove.guestagent.common import operating_system
from trove.guestagent.common.operating_system import FileMode
from trove.guestagent.datastore.mysql.service import MySqlApp
from trove.guestagent.strategies.replication import mysql_base
AGENT = BackupAgent()
LOG = logging.getLogger(__name__)
class MysqlBinlogReplication(mysql_base.MysqlReplicationBase):
"""MySql Replication coordinated by binlog position."""
class UnableToDetermineBinlogPosition(exception.TroveError):
message = _("Unable to determine binlog position "
"(from file %(binlog_file)s).")
def connect_to_master(self, service, snapshot):
logging_config = snapshot['log_position']
logging_config.update(self._read_log_position())
change_master_cmd = (
"CHANGE MASTER TO MASTER_HOST='%(host)s', "
"MASTER_PORT=%(port)s, "
"MASTER_USER='%(user)s', "
"MASTER_PASSWORD='%(password)s', "
"MASTER_LOG_FILE='%(log_file)s', "
"MASTER_LOG_POS=%(log_pos)s, "
"MASTER_CONNECT_RETRY=15" %
{
'host': snapshot['master']['host'],
'port': snapshot['master']['port'],
'user': logging_config['replication_user']['name'],
'password': logging_config['replication_user']['password'],
'log_file': logging_config['log_file'],
'log_pos': logging_config['log_position']
})
service.execute_on_client(change_master_cmd)
service.start_slave()
def _read_log_position(self):
INFO_FILE = ('%s/xtrabackup_binlog_info' % MySqlApp.get_data_dir())
LOG.info("Setting read permissions on %s", INFO_FILE)
operating_system.chmod(INFO_FILE, FileMode.ADD_READ_ALL, as_root=True)
LOG.info("Reading log position from %s", INFO_FILE)
try:
with open(INFO_FILE, 'rb') as f:
row = next(csv.reader(f, delimiter='\t',
skipinitialspace=True))
return {
'log_file': row[0],
'log_position': int(row[1])
}
except (IOError, IndexError) as ex:
LOG.exception(ex)
raise self.UnableToDetermineBinlogPosition(
{'binlog_file': INFO_FILE})