*: remove the support of the old ddl framework (#39684)

ref #39824

Makefile

@@ -408,10 +408,6 @@ bazel_coverage_test: failpoint-enable bazel_ci_prepare
 		--build_event_json_file=bazel_1.json --@io_bazel_rules_go//go/config:cover_format=go_cover \
 		-- //... -//cmd/... -//tests/graceshutdown/... \
 		-//tests/globalkilltest/... -//tests/readonlytest/... -//br/pkg/task:task_test -//tests/realtikvtest/...
-	bazel $(BAZEL_GLOBAL_CONFIG) coverage $(BAZEL_CMD_CONFIG) \
-		--build_event_json_file=bazel_2.json --@io_bazel_rules_go//go/config:cover_format=go_cover --define gotags=featuretag \
-		-- //... -//cmd/... -//tests/graceshutdown/... \
-		-//tests/globalkilltest/... -//tests/readonlytest/... -//br/pkg/task:task_test -//tests/realtikvtest/...
 
 bazel_build: bazel_ci_prepare
 	mkdir -p bin

br/pkg/conn/conn.go

@@ -191,7 +191,6 @@ func NewMgr(
 			return nil, errors.Trace(err)
 		}
 		// we must check tidb(tikv version) any time after concurrent ddl feature implemented in v6.2.
-		// when tidb < 6.2 we need set EnableConcurrentDDL false to make ddl works.
 		// we will keep this check until 7.0, which allow the breaking changes.
 		// NOTE: must call it after domain created!
 		// FIXME: remove this check in v7.0

br/pkg/version/BUILD.bazel

@@ -10,7 +10,6 @@ go_library(
         "//br/pkg/logutil",
         "//br/pkg/utils",
         "//br/pkg/version/build",
-        "//sessionctx/variable",
         "//util/engine",
         "@com_github_coreos_go_semver//semver",
         "@com_github_pingcap_errors//:errors",
@@ -29,7 +28,6 @@ go_test(
     flaky = True,
     deps = [
         "//br/pkg/version/build",
-        "//sessionctx/variable",
         "@com_github_coreos_go_semver//semver",
         "@com_github_data_dog_go_sqlmock//:go-sqlmock",
         "@com_github_pingcap_kvproto//pkg/metapb",

br/pkg/version/version.go

@@ -18,7 +18,6 @@ import (
 	"github.com/pingcap/tidb/br/pkg/logutil"
 	"github.com/pingcap/tidb/br/pkg/utils"
 	"github.com/pingcap/tidb/br/pkg/version/build"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/engine"
 	pd "github.com/tikv/pd/client"
 	"go.uber.org/zap"
@@ -166,9 +165,7 @@ func CheckVersionForDDL(s *metapb.Store, tikvVersion *semver.Version) error {
 	// use tikvVersion instead of tidbVersion since br doesn't have mysql client to connect tidb.
 	requireVersion := semver.New("6.2.0-alpha")
 	if tikvVersion.Compare(*requireVersion) < 0 {
-		log.Info("detected the old version of tidb cluster. set enable concurrent ddl to false")
-		variable.EnableConcurrentDDL.Store(false)
-		return nil
+		return errors.Errorf("detected the old version of tidb cluster, require: >= 6.2.0, but got %s", tikvVersion.String())
 	}
 	return nil
 }

br/pkg/version/version_test.go

@@ -13,7 +13,6 @@ import (
 	"github.com/coreos/go-semver/semver"
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pingcap/tidb/br/pkg/version/build"
-	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/stretchr/testify/require"
 	pd "github.com/tikv/pd/client"
 )
@@ -321,50 +320,40 @@ func TestCheckClusterVersion(t *testing.T) {
 		mock.getAllStores = func() []*metapb.Store {
 			return []*metapb.Store{{Version: "v6.4.0"}}
 		}
-		originVal := variable.EnableConcurrentDDL.Load()
 		err := CheckClusterVersion(context.Background(), &mock, CheckVersionForDDL)
 		require.NoError(t, err)
-		require.Equal(t, originVal, variable.EnableConcurrentDDL.Load())
 	}
 
 	{
 		mock.getAllStores = func() []*metapb.Store {
 			return []*metapb.Store{{Version: "v6.2.0"}}
 		}
-		originVal := variable.EnableConcurrentDDL.Load()
 		err := CheckClusterVersion(context.Background(), &mock, CheckVersionForDDL)
 		require.NoError(t, err)
-		require.Equal(t, originVal, variable.EnableConcurrentDDL.Load())
 	}
 
 	{
 		mock.getAllStores = func() []*metapb.Store {
 			return []*metapb.Store{{Version: "v6.2.0-alpha"}}
 		}
-		originVal := variable.EnableConcurrentDDL.Load()
 		err := CheckClusterVersion(context.Background(), &mock, CheckVersionForDDL)
 		require.NoError(t, err)
-		require.Equal(t, originVal, variable.EnableConcurrentDDL.Load())
 	}
 
 	{
 		mock.getAllStores = func() []*metapb.Store {
 			return []*metapb.Store{{Version: "v6.1.0"}}
 		}
-		variable.EnableConcurrentDDL.Store(true)
 		err := CheckClusterVersion(context.Background(), &mock, CheckVersionForDDL)
-		require.NoError(t, err)
-		require.False(t, variable.EnableConcurrentDDL.Load())
+		require.Error(t, err)
 	}
 
 	{
 		mock.getAllStores = func() []*metapb.Store {
 			return []*metapb.Store{{Version: "v5.4.0"}}
 		}
-		variable.EnableConcurrentDDL.Store(true)
 		err := CheckClusterVersion(context.Background(), &mock, CheckVersionForDDL)
-		require.NoError(t, err)
-		require.False(t, variable.EnableConcurrentDDL.Load())
+		require.Error(t, err)
 	}
 }
 

ddl/column.go

@@ -806,7 +806,7 @@ func doReorgWorkForModifyColumnMultiSchema(w *worker, d *ddlCtx, t *meta.Meta, j
 func doReorgWorkForModifyColumn(w *worker, d *ddlCtx, t *meta.Meta, job *model.Job, tbl table.Table,
 	oldCol, changingCol *model.ColumnInfo, changingIdxs []*model.IndexInfo) (done bool, ver int64, err error) {
 	job.ReorgMeta.ReorgTp = model.ReorgTypeTxn
-	rh := newReorgHandler(t, w.sess, w.concurrentDDL)
+	rh := newReorgHandler(t, w.sess)
 	dbInfo, err := t.GetDatabase(job.SchemaID)
 	if err != nil {
 		return false, ver, errors.Trace(err)