// NewDBConnection returns a new DBConnection based on the ConnParams
// and will use the provided stats to collect timing.
func NewDBConnection(info *sqldb.ConnParams, mysqlStats *stats.Timings) (*DBConnection, error) {
params, err := dbconfigs.MysqlParams(info)
if err != nil {
return nil, err
}
c, err := sqldb.Connect(params)
return &DBConnection{c, mysqlStats}, err
}
// Connect connects to a db server
func (dc *DBClient) Connect() error {
params, err := dbconfigs.MysqlParams(dc.dbConfig)
if err != nil {
return err
}
dc.dbConn, err = sqldb.Connect(params)
if err != nil {
return fmt.Errorf("error in connecting to mysql db, err %v", err)
}
return nil
}
// connectForReplication create a MySQL connection ready to use for replication.
func (mysqld *Mysqld) connectForReplication() (sqldb.Conn, error) {
params, err := dbconfigs.MysqlParams(mysqld.dba)
if err != nil {
return nil, err
}
conn, err := sqldb.Connect(params)
if err != nil {
return nil, err
}
// Tell the server that we understand the format of events
// that will be used if binlog_checksum is enabled on the server.
if _, err := conn.ExecuteFetch("SET @master_binlog_checksum=@@global.binlog_checksum", 0, false); err != nil {
return nil, fmt.Errorf("failed to set @master_binlog_checksum=@@global.binlog_checksum: %v", err)
}
return conn, nil
}
// NewSlaveConnection creates a new slave connection to the mysqld instance.
// It uses a pools.IDPool to ensure that the server IDs used to connect are
// unique within this process. This is done with the assumptions that:
//
// 1) No other processes are making fake slave connections to our mysqld.
// 2) No real slave servers will have IDs in the range 1-N where N is the peak
// number of concurrent fake slave connections we will ever make.
func (mysqld *Mysqld) NewSlaveConnection() (*SlaveConnection, error) {
params, err := dbconfigs.MysqlParams(mysqld.dba)
if err != nil {
return nil, err
}
conn, err := sqldb.Connect(params)
if err != nil {
return nil, err
}
sc := &SlaveConnection{
Conn: conn,
mysqld: mysqld,
slaveID: slaveIDPool.Get(),
}
log.Infof("new slave connection: slaveID=%d", sc.slaveID)
return sc, nil
}