parser/executor: admin show/set bdr role (pingcap#48504)

ref pingcap#48519

pkg/executor/builder.go

@@ -317,6 +317,8 @@ func (b *executorBuilder) build(p plannercore.Plan) exec.Executor {
 		return b.buildCTETableReader(v)
 	case *plannercore.CompactTable:
 		return b.buildCompactTable(v)
+	case *plannercore.AdminShowBDRRole:
+		return b.buildAdminShowBDRRole(v)
 	default:
 		if mp, ok := p.(MockPhysicalPlan); ok {
 			return mp.GetExecutor()
@@ -5489,3 +5491,7 @@ func (b *executorBuilder) buildCompactTable(v *plannercore.CompactTable) exec.Ex
 		tikvStore:    tikvStore,
 	}
 }
+
+func (b *executorBuilder) buildAdminShowBDRRole(v *plannercore.AdminShowBDRRole) exec.Executor {
+	return &AdminShowBDRRoleExec{BaseExecutor: exec.NewBaseExecutor(b.ctx, v.Schema(), v.ID())}
+}

pkg/executor/executor.go

@@ -112,6 +112,7 @@ var (
 	_ exec.Executor = &sortexec.TopNExec{}
 	_ exec.Executor = &UnionExec{}
 	_ exec.Executor = &FastCheckTableExec{}
+	_ exec.Executor = &AdminShowBDRRoleExec{}
 
 	// GlobalMemoryUsageTracker is the ancestor of all the Executors' memory tracker and GlobalMemory Tracker
 	GlobalMemoryUsageTracker *memory.Tracker
@@ -2751,3 +2752,33 @@ func ColumnName(column string) string {
 func escapeName(name string) string {
 	return strings.ReplaceAll(name, "`", "``")
 }
+
+// AdminShowBDRRoleExec represents a show BDR role executor.
+type AdminShowBDRRoleExec struct {
+	exec.BaseExecutor
+
+	done bool
+}
+
+// Next implements the Executor Next interface.
+func (e *AdminShowBDRRoleExec) Next(ctx context.Context, req *chunk.Chunk) error {
+	req.Reset()
+	if e.done {
+		return nil
+	}
+
+	return kv.RunInNewTxn(kv.WithInternalSourceType(ctx, kv.InternalTxnAdmin), e.Ctx().GetStore(), true, func(ctx context.Context, txn kv.Transaction) error {
+		role, err := meta.NewMeta(txn).GetBDRRole()
+		if err != nil {
+			return err
+		}
+
+		if role == "" {
+			role = string(ast.BDRRoleNone)
+		}
+
+		req.AppendString(0, role)
+		e.done = true
+		return nil
+	})
+}

pkg/executor/simple.go

@@ -41,6 +41,7 @@ import (
 	"github.com/pingcap/tidb/pkg/expression"
 	"github.com/pingcap/tidb/pkg/infoschema"
 	"github.com/pingcap/tidb/pkg/kv"
+	"github.com/pingcap/tidb/pkg/meta"
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/auth"
 	"github.com/pingcap/tidb/pkg/parser/model"
@@ -2786,6 +2787,8 @@ func (e *SimpleExec) executeAdmin(s *ast.AdminStmt) error {
 		return e.executeAdminReloadStatistics(s)
 	case ast.AdminFlushPlanCache:
 		return e.executeAdminFlushPlanCache(s)
+	case ast.AdminSetBDRRole:
+		return e.executeAdminSetBDRRole(s)
 	}
 	return nil
 }
@@ -2822,6 +2825,16 @@ func (e *SimpleExec) executeAdminFlushPlanCache(s *ast.AdminStmt) error {
 	return nil
 }
 
+func (e *SimpleExec) executeAdminSetBDRRole(s *ast.AdminStmt) error {
+	if s.Tp != ast.AdminSetBDRRole {
+		return errors.New("This AdminStmt is not ADMIN SET BDR_ROLE")
+	}
+
+	return kv.RunInNewTxn(kv.WithInternalSourceType(context.Background(), kv.InternalTxnAdmin), e.Ctx().GetStore(), true, func(ctx context.Context, txn kv.Transaction) error {
+		return errors.Trace(meta.NewMeta(txn).SetBDRRole(string(s.BDRRole)))
+	})
+}
+
 func (e *SimpleExec) executeSetResourceGroupName(s *ast.SetResourceGroupStmt) error {
 	if s.Name.L != "" {
 		if _, ok := e.is.ResourceGroupByName(s.Name); !ok {

pkg/meta/BUILD.bazel

@@ -34,6 +34,7 @@ go_test(
     shard_count = 12,
     deps = [
         "//pkg/kv",
+        "//pkg/parser/ast",
         "//pkg/parser/model",
         "//pkg/store/mockstore",
         "//pkg/testkit/testsetup",

pkg/meta/meta.go

@@ -78,6 +78,7 @@ var (
 	mPolicyGlobalID      = []byte("PolicyGlobalID")
 	mPolicyMagicByte     = CurrentMagicByteVer
 	mDDLTableVersion     = []byte("DDLTableVersion")
+	mBDRRole             = []byte("BDRRole")
 	mMetaDataLock        = []byte("metadataLock")
 	// the id for 'default' group, the internal ddl can ensure
 	// user created resource group won't duplicate with this id.
@@ -680,10 +681,23 @@ func (m *Meta) CreateTableOrView(dbID int64, tableInfo *model.TableInfo) error {
 	return m.txn.HSet(dbKey, tableKey, data)
 }
 
+// SetBDRRole write BDR role into storage.
+func (m *Meta) SetBDRRole(role string) error {
+	return errors.Trace(m.txn.Set(mBDRRole, []byte(role)))
+}
+
+// GetBDRRole get BDR role from storage.
+func (m *Meta) GetBDRRole() (string, error) {
+	v, err := m.txn.Get(mBDRRole)
+	if err != nil {
+		return "", errors.Trace(err)
+	}
+	return string(v), nil
+}
+
 // SetDDLTables write a key into storage.
 func (m *Meta) SetDDLTables(ddlTableVersion DDLTableVersion) error {
-	err := m.txn.Set(mDDLTableVersion, ddlTableVersion.Bytes())
-	return errors.Trace(err)
+	return errors.Trace(m.txn.Set(mDDLTableVersion, ddlTableVersion.Bytes()))
 }
 
 // CheckDDLTableVersion check if the tables related to concurrent DDL exists.

pkg/meta/meta_test.go

@@ -24,6 +24,7 @@ import (
 	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/pkg/kv"
 	"github.com/pingcap/tidb/pkg/meta"
+	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/model"
 	"github.com/pingcap/tidb/pkg/store/mockstore"
 	"github.com/pingcap/tidb/pkg/util"
@@ -446,6 +447,15 @@ func TestMeta(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, schemaDiff, readDiff)
 
+	// Test for BDR role
+	role, err := m.GetBDRRole()
+	require.NoError(t, err)
+	require.Len(t, role, 0)
+	require.NoError(t, m.SetBDRRole(string(ast.BDRRolePrimary)))
+	role, err = m.GetBDRRole()
+	require.NoError(t, err)
+	require.Equal(t, string(ast.BDRRolePrimary), role)
+
 	err = txn.Commit(context.Background())
 	require.NoError(t, err)
 

pkg/parser/ast/misc.go

@@ -2305,7 +2305,7 @@ type AdminStmtType int
 
 // Admin statement types.
 const (
-	AdminShowDDL = iota + 1
+	AdminShowDDL AdminStmtType = iota + 1
 	AdminCheckTable
 	AdminShowDDLJobs
 	AdminCancelDDLJobs
@@ -2332,6 +2332,8 @@ const (
 	AdminResetTelemetryID
 	AdminReloadStatistics
 	AdminFlushPlanCache
+	AdminSetBDRRole
+	AdminShowBDRRole
 )
 
 // HandleRange represents a range where handle value >= Begin and < End.
@@ -2340,6 +2342,16 @@ type HandleRange struct {
 	End   int64
 }
 
+// BDRRole represents the role of the cluster in BDR mode.
+type BDRRole string
+
+const (
+	BDRRoleNone      BDRRole = "none"
+	BDRRolePrimary   BDRRole = "primary"
+	BDRRoleSecondary BDRRole = "secondary"
+	BDRRoleLocalOnly BDRRole = "local_only"
+)
+
 type StatementScope int
 
 const (
@@ -2427,6 +2439,7 @@ type AdminStmt struct {
 	Where          ExprNode
 	StatementScope StatementScope
 	LimitSimple    LimitSimple
+	BDRRole        BDRRole
 }
 
 // Restore implements Node interface.
@@ -2581,6 +2594,21 @@ func (n *AdminStmt) Restore(ctx *format.RestoreCtx) error {
 		} else if n.StatementScope == StatementScopeGlobal {
 			ctx.WriteKeyWord("FLUSH GLOBAL PLAN_CACHE")
 		}
+	case AdminSetBDRRole:
+		switch n.BDRRole {
+		case BDRRoleNone:
+			ctx.WriteKeyWord("SET BDR ROLE NONE")
+		case BDRRolePrimary:
+			ctx.WriteKeyWord("SET BDR ROLE PRIMARY")
+		case BDRRoleSecondary:
+			ctx.WriteKeyWord("SET BDR ROLE SECONDARY")
+		case BDRRoleLocalOnly:
+			ctx.WriteKeyWord("SET BDR ROLE LOCAL_ONLY")
+		default:
+			return errors.New("Unsupported BDR role")
+		}
+	case AdminShowBDRRole:
+		ctx.WriteKeyWord("SHOW BDR ROLE")
 	default:
 		return errors.New("Unsupported AdminStmt type")
 	}

pkg/parser/misc.go

@@ -184,6 +184,7 @@ var tokenMap = map[string]int{
 	"BACKEND":                  backend,
 	"BACKUP":                   backup,
 	"BACKUPS":                  backups,
+	"BDR":                      bdr,
 	"BEGIN":                    begin,
 	"BETWEEN":                  between,
 	"BERNOULLI":                bernoulli,
@@ -491,6 +492,7 @@ var tokenMap = map[string]int{
 	"LOCAL":                    local,
 	"LOCALTIME":                localTime,
 	"LOCALTIMESTAMP":           localTs,
+	"LOCAL_ONLY":               local_only,
 	"LOCATION":                 location,
 	"LOCK":                     lock,
 	"LOCKED":                   locked,
@@ -684,6 +686,7 @@ var tokenMap = map[string]int{
 	"SCHEMAS":                  databases,
 	"SECOND_MICROSECOND":       secondMicrosecond,
 	"SECOND":                   second,
+	"SECONDARY":                secondary,
 	"SECONDARY_ENGINE":         secondaryEngine,
 	"SECONDARY_LOAD":           secondaryLoad,
 	"SECONDARY_UNLOAD":         secondaryUnload,