session: set tidb_opt_range_max_size to 0 when upgrading to v6.4.0+

session/bootstrap.go

@@ -637,11 +637,14 @@ const (
 	version95 = 95
 	// version96 converts server-memory-quota to a sysvar
 	version96 = 96
+	// version97 sets tidb_opt_range_max_size to 0 when a cluster upgrades from some version lower than v6.4.0 to v6.4.0+.
+	// It promises the compatibility of building ranges behavior.
+	version97 = 97
 )
 
 // currentBootstrapVersion is defined as a variable, so we can modify its value for testing.
 // please make sure this is the largest version
-var currentBootstrapVersion int64 = version95
+var currentBootstrapVersion int64 = version97
 
 // DDL owner key's expired time is ManagerSessionTTL seconds, we should wait the time and give more time to have a chance to finish it.
 var internalSQLTimeout = owner.ManagerSessionTTL + 15
@@ -743,6 +746,7 @@ var (
 		upgradeToVer94,
 		upgradeToVer95,
 		upgradeToVer96,
+		upgradeToVer97,
 	}
 )
 
@@ -1953,6 +1957,27 @@ func upgradeToVer96(s Session, ver int64) {
 	importConfigOption(s, "performance.server-memory-quota", variable.TiDBServerMemoryLimit, valStr)
 }
 
+func upgradeToVer97(s Session, ver int64) {
+	if ver >= version97 {
+		return
+	}
+	// Check if tidb_opt_range_max_size exists in mysql.GLOBAL_VARIABLES.
+	// If not, insert "tidb_opt_range_max_size | 0" since this is the old behavior before we introduce this variable.
+	ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnBootstrap)
+	rs, err := s.ExecuteInternal(ctx, "SELECT VARIABLE_VALUE FROM %n.%n WHERE VARIABLE_NAME=%?;",
+		mysql.SystemDB, mysql.GlobalVariablesTable, variable.TiDBOptRangeMaxSize)
+	terror.MustNil(err)
+	req := rs.NewChunk(nil)
+	err = rs.Next(ctx, req)
+	terror.MustNil(err)
+	if req.NumRows() != 0 {
+		return
+	}
+
+	mustExecute(s, "INSERT HIGH_PRIORITY IGNORE INTO %n.%n VALUES (%?, %?);",
+		mysql.SystemDB, mysql.GlobalVariablesTable, variable.TiDBOptRangeMaxSize, 0)
+}
+
 func writeOOMAction(s Session) {
 	comment := "oom-action is `log` by default in v3.0.x, `cancel` by default in v4.0.11+"
 	mustExecute(s, `INSERT HIGH_PRIORITY INTO %n.%n VALUES (%?, %?, %?) ON DUPLICATE KEY UPDATE VARIABLE_VALUE= %?`,

session/bootstrap_test.go

@@ -1055,3 +1055,61 @@ func TestTiDBEnablePagingVariable(t *testing.T) {
 		r.Close()
 	}
 }
+
+func TestTiDBOptRangeMaxSizeWhenUpgrading(t *testing.T) {
+	ctx := context.Background()
+	store, dom := createStoreAndBootstrap(t)
+	defer func() { require.NoError(t, store.Close()) }()
+
+	// Upgrade from v6.3.0 to v6.4.0+.
+	ver94 := 94
+	seV630 := createSessionAndSetID(t, store)
+	txn, err := store.Begin()
+	require.NoError(t, err)
+	m := meta.NewMeta(txn)
+	err = m.FinishBootstrap(int64(ver94))
+	require.NoError(t, err)
+	err = txn.Commit(context.Background())
+	require.NoError(t, err)
+	mustExec(t, seV630, fmt.Sprintf("update mysql.tidb set variable_value=%d where variable_name='tidb_server_version'", ver94))
+	mustExec(t, seV630, fmt.Sprintf("delete from mysql.GLOBAL_VARIABLES where variable_name='%s'", variable.TiDBOptRangeMaxSize))
+	mustExec(t, seV630, "commit")
+	unsetStoreBootstrapped(store.UUID())
+	ver, err := getBootstrapVersion(seV630)
+	require.NoError(t, err)
+	require.Equal(t, int64(ver94), ver)
+
+	// We are now in 6.3.0, check tidb_opt_range_max_size should not exist.
+	res := mustExec(t, seV630, fmt.Sprintf("select * from mysql.GLOBAL_VARIABLES where variable_name='%s'", variable.TiDBOptRangeMaxSize))
+	chk := res.NewChunk(nil)
+	err = res.Next(ctx, chk)
+	require.NoError(t, err)
+	require.Equal(t, 0, chk.NumRows())
+	dom.Close()
+	domCurVer, err := BootstrapSession(store)
+	require.NoError(t, err)
+	defer domCurVer.Close()
+	seCurVer := createSessionAndSetID(t, store)
+	ver, err = getBootstrapVersion(seCurVer)
+	require.NoError(t, err)
+	require.Equal(t, currentBootstrapVersion, ver)
+
+	// We are now in version no lower than v6.4.0, tidb_opt_range_max_size should be 0.
+	res = mustExec(t, seCurVer, "select @@session.tidb_opt_range_max_size")
+	chk = res.NewChunk(nil)
+	err = res.Next(ctx, chk)
+	require.NoError(t, err)
+	require.Equal(t, 1, chk.NumRows())
+	row := chk.GetRow(0)
+	require.Equal(t, 1, row.Len())
+	require.Equal(t, "0", row.GetString(0))
+
+	res = mustExec(t, seCurVer, "select @@global.tidb_opt_range_max_size")
+	chk = res.NewChunk(nil)
+	err = res.Next(ctx, chk)
+	require.NoError(t, err)
+	require.Equal(t, 1, chk.NumRows())
+	row = chk.GetRow(0)
+	require.Equal(t, 1, row.Len())
+	require.Equal(t, "0", row.GetString(0))
+}