storage/mysql: support pre-5.7.20 instances with tx_isolation only

This commit is contained in:
Nandor Kracser 2019-09-23 09:36:01 +02:00
parent 8427f0f15c
commit d2c33db8a8

View file

@ -29,6 +29,7 @@ const (
// MySQL error codes
mysqlErrDupEntry = 1062
mysqlErrDupEntryWithKeyName = 1586
mysqlErrUnknownSysVar = 1193
)
// SQLite3 options for creating an SQL db.
@ -307,6 +308,26 @@ func (s *MySQL) open(logger log.Logger) (*conn, error) {
return nil, err
}
err = db.Ping()
if err != nil {
if mysqlErr, ok := err.(*mysql.MySQLError); ok && mysqlErr.Number == mysqlErrUnknownSysVar {
logger.Info("reconnecting with MySQL pre-5.7.20 compatibilty mode")
// MySQL 5.7.20 introduced transaction_isolation and deprecated tx_isolation.
// MySQL 8.0 doesn't have tx_isolation at all.
// https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_transaction_isolation
delete(cfg.Params, "transaction_isolation")
cfg.Params["tx_isolation"] = "'SERIALIZABLE'"
db, err = sql.Open("mysql", cfg.FormatDSN())
if err != nil {
return nil, err
}
} else {
return nil, err
}
}
errCheck := func(err error) bool {
sqlErr, ok := err.(*mysql.MySQLError)
if !ok {