Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

ddl: fix concurrent column type changes(with changing data) that cause schema and data inconsistencies #31051

Merged
merged 5 commits into from
Dec 28, 2021
Merged
Show file tree
Hide file tree
Changes from 4 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 7 additions & 3 deletions ddl/column.go
Original file line number Diff line number Diff line change
Expand Up @@ -847,7 +847,7 @@ func (w *worker) onModifyColumn(d *ddlCtx, t *meta.Meta, job *model.Job) (ver in
if job.IsRollingback() {
// For those column-type-change jobs which don't reorg the data.
if !needChangeColumnData(oldCol, jobParam.newCol) {
return rollbackModifyColumnJob(t, tblInfo, job, oldCol, jobParam.modifyColumnTp)
return rollbackModifyColumnJob(t, tblInfo, job, jobParam.newCol, oldCol, jobParam.modifyColumnTp)
}
// For those column-type-change jobs which reorg the data.
return rollbackModifyColumnJobWithData(t, tblInfo, job, oldCol, jobParam)
Expand Down Expand Up @@ -1483,6 +1483,10 @@ func updateChangingInfo(changingCol *model.ColumnInfo, changingIdxs []*model.Ind
func (w *worker) doModifyColumn(
d *ddlCtx, t *meta.Meta, job *model.Job, dbInfo *model.DBInfo, tblInfo *model.TableInfo,
newCol, oldCol *model.ColumnInfo, pos *ast.ColumnPosition) (ver int64, _ error) {
if oldCol.ID != newCol.ID {
job.State = model.JobStateRollingback
return ver, errKeyColumnDoesNotExits.GenWithStack("column %s id %d does not exist, this column may have been updated by other DDL ran in parallel", oldCol.Name, newCol.ID)
}
// Column from null to not null.
if !mysql.HasNotNullFlag(oldCol.Flag) && mysql.HasNotNullFlag(newCol.Flag) {
noPreventNullFlag := !mysql.HasPreventNullInsertFlag(oldCol.Flag)
Expand Down Expand Up @@ -1804,9 +1808,9 @@ func checkAddColumnTooManyColumns(colNum int) error {
}

// rollbackModifyColumnJob rollbacks the job when an error occurs.
func rollbackModifyColumnJob(t *meta.Meta, tblInfo *model.TableInfo, job *model.Job, oldCol *model.ColumnInfo, modifyColumnTp byte) (ver int64, _ error) {
func rollbackModifyColumnJob(t *meta.Meta, tblInfo *model.TableInfo, job *model.Job, newCol, oldCol *model.ColumnInfo, modifyColumnTp byte) (ver int64, _ error) {
var err error
if modifyColumnTp == mysql.TypeNull {
if oldCol.ID == newCol.ID && modifyColumnTp == mysql.TypeNull {
// field NotNullFlag flag reset.
tblInfo.Columns[oldCol.Offset].Flag = oldCol.Flag &^ mysql.NotNullFlag
// field PreventNullInsertFlag flag reset.
Expand Down
53 changes: 52 additions & 1 deletion ddl/db_change_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -1062,6 +1062,54 @@ func (s *testStateChangeSuite) TestParallelAlterModifyColumn(c *C) {
s.testControlParallelExecSQL(c, sql, sql, f)
}

func (s *testStateChangeSuite) TestParallelAlterModifyColumnWithData(c *C) {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can we add more tests about concurrent alter table? For example, random test.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Could you give an example of this random test? I don't think it's appropriate to add it here.

sql := "ALTER TABLE t MODIFY COLUMN c int;"
f := func(c *C, err1, err2 error) {
c.Assert(err1, IsNil)
c.Assert(err2.Error(), Equals, "[ddl:1072]column c id 3 does not exist, this column may have been updated by other DDL ran in parallel")
rs, err := s.se.Execute(context.Background(), "select * from t")
c.Assert(err, IsNil)
sRows, err := session.ResultSetToStringSlice(context.Background(), s.se, rs[0])
c.Assert(err, IsNil)
c.Assert(sRows[0][2], Equals, "3")
c.Assert(rs[0].Close(), IsNil)
_, err = s.se.Execute(context.Background(), "insert into t values(11, 22, 33.3, 44, 55)")
c.Assert(err, IsNil)
rs, err = s.se.Execute(context.Background(), "select * from t")
c.Assert(err, IsNil)
sRows, err = session.ResultSetToStringSlice(context.Background(), s.se, rs[0])
c.Assert(err, IsNil)
c.Assert(sRows[1][2], Equals, "33")
c.Assert(rs[0].Close(), IsNil)
}
s.testControlParallelExecSQL(c, sql, sql, f)
}

func (s *testStateChangeSuite) TestParallelAlterModifyColumnToNotNullWithData(c *C) {
sql := "ALTER TABLE t MODIFY COLUMN c int not null;"
f := func(c *C, err1, err2 error) {
c.Assert(err1, IsNil)
c.Assert(err2.Error(), Equals, "[ddl:1072]column c id 3 does not exist, this column may have been updated by other DDL ran in parallel")
rs, err := s.se.Execute(context.Background(), "select * from t")
c.Assert(err, IsNil)
sRows, err := session.ResultSetToStringSlice(context.Background(), s.se, rs[0])
c.Assert(err, IsNil)
c.Assert(sRows[0][2], Equals, "3")
c.Assert(rs[0].Close(), IsNil)
_, err = s.se.Execute(context.Background(), "insert into t values(11, 22, null, 44, 55)")
c.Assert(err, NotNil)
_, err = s.se.Execute(context.Background(), "insert into t values(11, 22, 33.3, 44, 55)")
c.Assert(err, IsNil)
rs, err = s.se.Execute(context.Background(), "select * from t")
c.Assert(err, IsNil)
sRows, err = session.ResultSetToStringSlice(context.Background(), s.se, rs[0])
c.Assert(err, IsNil)
c.Assert(sRows[1][2], Equals, "33")
c.Assert(rs[0].Close(), IsNil)
}
s.testControlParallelExecSQL(c, sql, sql, f)
}

func (s *testStateChangeSuite) TestParallelAddGeneratedColumnAndAlterModifyColumn(c *C) {
sql1 := "ALTER TABLE t ADD COLUMN f INT GENERATED ALWAYS AS(a+1);"
sql2 := "ALTER TABLE t MODIFY COLUMN a tinyint;"
Expand Down Expand Up @@ -1337,12 +1385,15 @@ func (s *testStateChangeSuiteBase) prepareTestControlParallelExecSQL(c *C) (sess
func (s *testStateChangeSuiteBase) testControlParallelExecSQL(c *C, sql1, sql2 string, f checkRet) {
_, err := s.se.Execute(context.Background(), "use test_db_state")
c.Assert(err, IsNil)
_, err = s.se.Execute(context.Background(), "create table t(a int, b int, c int, d int auto_increment,e int, index idx1(d), index idx2(d,e))")
_, err = s.se.Execute(context.Background(), "create table t(a int, b int, c double default null, d int auto_increment,e int, index idx1(d), index idx2(d,e))")
c.Assert(err, IsNil)
if len(s.preSQL) != 0 {
_, err := s.se.Execute(context.Background(), s.preSQL)
c.Assert(err, IsNil)
}
_, err = s.se.Execute(context.Background(), "insert into t values(1, 2, 3.1234, 4, 5)")
c.Assert(err, IsNil)

defer func() {
_, err := s.se.Execute(context.Background(), "drop table t")
c.Assert(err, IsNil)
Expand Down