variable: fix information_schema.VARIABLES_INFO DEFAULT_VALUE not rig…

…ht problem (#49524)

close #49461, close #49968, close #50155

pkg/executor/infoschema_reader.go

@@ -264,10 +264,14 @@ func (e *memtableRetriever) setDataForVariablesInfo(ctx sessionctx.Context) erro
 		if sv.IsNoop {
 			isNoop = "YES"
 		}
+		defVal := sv.Value
+		if sv.HasGlobalScope() {
+			defVal = variable.GlobalSystemVariableInitialValue(sv.Name, defVal)
+		}
 		row := types.MakeDatums(
 			sv.Name,           // VARIABLE_NAME
 			sv.Scope.String(), // VARIABLE_SCOPE
-			sv.Value,          // DEFAULT_VALUE
+			defVal,            // DEFAULT_VALUE
 			currentVal,        // CURRENT_VALUE
 			sv.MinValue,       // MIN_VALUE
 			sv.MaxValue,       // MAX_VALUE

pkg/executor/set.go

@@ -301,7 +301,8 @@ func (e *SetExecutor) getVarValue(ctx context.Context, v *expression.VarAssignme
 		// to the compiled-in MySQL default value, use the DEFAULT keyword.
 		// See http://dev.mysql.com/doc/refman/5.7/en/set-statement.html
 		if sysVar != nil {
-			return sysVar.Value, nil
+			defVal := variable.GlobalSystemVariableInitialValue(sysVar.Name, sysVar.Value)
+			return defVal, nil
 		}
 		return e.Ctx().GetSessionVars().GetGlobalSystemVar(ctx, v.Name)
 	}

pkg/session/bootstrap.go

@@ -3194,37 +3194,7 @@ func doDMLWorks(s sessiontypes.Session) {
 		if !v.HasGlobalScope() {
 			continue
 		}
-		vVal := v.Value
-		switch v.Name {
-		case variable.TiDBTxnMode:
-			if config.GetGlobalConfig().Store == "tikv" || config.GetGlobalConfig().Store == "unistore" {
-				vVal = "pessimistic"
-			}
-		case variable.TiDBEnableAsyncCommit, variable.TiDBEnable1PC:
-			if config.GetGlobalConfig().Store == "tikv" {
-				vVal = variable.On
-			}
-		case variable.TiDBMemOOMAction:
-			if intest.InTest {
-				vVal = variable.OOMActionLog
-			}
-		case variable.TiDBEnableAutoAnalyze:
-			if intest.InTest {
-				vVal = variable.Off
-			}
-		// For the following sysvars, we change the default
-		// FOR NEW INSTALLS ONLY. In most cases you don't want to do this.
-		// It is better to change the value in the Sysvar struct, so that
-		// all installs will have the same value.
-		case variable.TiDBRowFormatVersion:
-			vVal = strconv.Itoa(variable.DefTiDBRowFormatV2)
-		case variable.TiDBTxnAssertionLevel:
-			vVal = variable.AssertionFastStr
-		case variable.TiDBEnableMutationChecker:
-			vVal = variable.On
-		case variable.TiDBPessimisticTransactionFairLocking:
-			vVal = variable.On
-		}
+		vVal := variable.GlobalSystemVariableInitialValue(v.Name, v.Value)
 
 		// sanitize k and vVal
 		value := fmt.Sprintf(`("%s", "%s")`, sqlescape.EscapeString(k), sqlescape.EscapeString(vVal))

pkg/session/test/variable/variable_test.go

@@ -121,6 +121,8 @@ func TestCoprocessorOOMAction(t *testing.T) {
 	disableOOM := func(tk *testkit.TestKit, name, sql string) {
 		t.Logf("disable OOM, testcase: %v", name)
 		quota := 5*copr.MockResponseSizeForTest - 100
+		tk.MustExec("SET GLOBAL tidb_mem_oom_action='CANCEL'")
+		defer tk.MustExec("SET GLOBAL tidb_mem_oom_action = DEFAULT")
 		tk.MustExec("use testoom")
 		tk.MustExec("set @@tidb_enable_rate_limit_action=0")
 		tk.MustExec("set @@tidb_distsql_scan_concurrency = 10")
@@ -172,9 +174,11 @@ func TestCoprocessorOOMAction(t *testing.T) {
 		tk.MustExec("use testoom")
 		tk.MustExec("set tidb_distsql_scan_concurrency = 1")
 		tk.MustExec("set @@tidb_mem_quota_query=1;")
+		tk.MustExec("SET GLOBAL tidb_mem_oom_action='CANCEL'")
 		err = tk.QueryToErr(testcase.sql)
 		require.Error(t, err)
 		require.True(t, exeerrors.ErrMemoryExceedForQuery.Equal(err))
+		tk.MustExec("SET GLOBAL tidb_mem_oom_action = DEFAULT")
 		se.Close()
 	}
 }

pkg/sessionctx/variable/BUILD.bazel

@@ -50,6 +50,7 @@ go_library(
         "//pkg/util/distrole",
         "//pkg/util/execdetails",
         "//pkg/util/gctuner",
+        "//pkg/util/intest",
         "//pkg/util/kvcache",
         "//pkg/util/logutil",
         "//pkg/util/mathutil",

pkg/sessionctx/variable/sysvar.go

@@ -44,6 +44,7 @@ import (
 	"github.com/pingcap/tidb/pkg/util/collate"
 	distroleutil "github.com/pingcap/tidb/pkg/util/distrole"
 	"github.com/pingcap/tidb/pkg/util/gctuner"
+	"github.com/pingcap/tidb/pkg/util/intest"
 	"github.com/pingcap/tidb/pkg/util/logutil"
 	"github.com/pingcap/tidb/pkg/util/mathutil"
 	"github.com/pingcap/tidb/pkg/util/memory"
@@ -3002,6 +3003,37 @@ var defaultSysVars = []*SysVar{
 		}},
 }
 
+// GlobalSystemVariableInitialValue gets the default value for a system variable including ones that are dynamically set (e.g. based on the store)
+func GlobalSystemVariableInitialValue(varName, varVal string) string {
+	switch varName {
+	case TiDBEnableAsyncCommit, TiDBEnable1PC:
+		if config.GetGlobalConfig().Store == "tikv" {
+			varVal = On
+		}
+	case TiDBMemOOMAction:
+		if intest.InTest {
+			varVal = OOMActionLog
+		}
+	case TiDBEnableAutoAnalyze:
+		if intest.InTest {
+			varVal = Off
+		}
+	// For the following sysvars, we change the default
+	// FOR NEW INSTALLS ONLY. In most cases you don't want to do this.
+	// It is better to change the value in the Sysvar struct, so that
+	// all installs will have the same value.
+	case TiDBRowFormatVersion:
+		varVal = strconv.Itoa(DefTiDBRowFormatV2)
+	case TiDBTxnAssertionLevel:
+		varVal = AssertionFastStr
+	case TiDBEnableMutationChecker:
+		varVal = On
+	case TiDBPessimisticTransactionFairLocking:
+		varVal = On
+	}
+	return varVal
+}
+
 func setTiFlashComputeDispatchPolicy(s *SessionVars, val string) error {
 	p, err := tiflashcompute.GetDispatchPolicyByStr(val)
 	if err != nil {

pkg/sessionctx/variable/sysvar_test.go

@@ -1453,3 +1453,61 @@ func TestSetTiDBCloudStorageURI(t *testing.T) {
 	require.Len(t, val, 0)
 	cancel()
 }
+
+func TestGlobalSystemVariableInitialValue(t *testing.T) {
+	vars := []struct {
+		name    string
+		val     string
+		initVal string
+	}{
+		{
+			TiDBTxnMode,
+			DefTiDBTxnMode,
+			"pessimistic",
+		},
+		{
+			TiDBEnableAsyncCommit,
+			BoolToOnOff(DefTiDBEnableAsyncCommit),
+			BoolToOnOff(DefTiDBEnableAsyncCommit),
+		},
+		{
+			TiDBEnable1PC,
+			BoolToOnOff(DefTiDBEnable1PC),
+			BoolToOnOff(DefTiDBEnable1PC),
+		},
+		{
+			TiDBMemOOMAction,
+			DefTiDBMemOOMAction,
+			OOMActionLog,
+		},
+		{
+			TiDBEnableAutoAnalyze,
+			BoolToOnOff(DefTiDBEnableAutoAnalyze),
+			Off,
+		},
+		{
+			TiDBRowFormatVersion,
+			strconv.Itoa(DefTiDBRowFormatV1),
+			strconv.Itoa(DefTiDBRowFormatV2),
+		},
+		{
+			TiDBTxnAssertionLevel,
+			DefTiDBTxnAssertionLevel,
+			AssertionFastStr,
+		},
+		{
+			TiDBEnableMutationChecker,
+			BoolToOnOff(DefTiDBEnableMutationChecker),
+			On,
+		},
+		{
+			TiDBPessimisticTransactionFairLocking,
+			BoolToOnOff(DefTiDBPessimisticTransactionFairLocking),
+			On,
+		},
+	}
+	for _, v := range vars {
+		initVal := GlobalSystemVariableInitialValue(v.name, v.val)
+		require.Equal(t, v.initVal, initVal)
+	}
+}

tests/integrationtest/r/executor/infoschema_reader.result

@@ -283,3 +283,31 @@ SELECT * FROM information_schema.user_privileges WHERE grantee="'usageuser'@'%'"
 GRANTEE	TABLE_CATALOG	PRIVILEGE_TYPE	IS_GRANTABLE
 'usageuser'@'%'	def	BACKUP_ADMIN	NO
 'usageuser'@'%'	def	SELECT	YES
+select VARIABLE_NAME from information_schema.VARIABLES_INFO where DEFAULT_VALUE = CURRENT_VALUE and variable_name in ('tidb_enable_async_commit','tidb_enable_1pc', 'tidb_mem_oom_action', 'tidb_enable_auto_analyze', 'tidb_row_format_version', 'tidb_txn_assertion_level', 'tidb_enable_mutation_checker', 'tidb_pessimistic_txn_fair_locking') order by VARIABLE_NAME;
+VARIABLE_NAME
+tidb_enable_1pc
+tidb_enable_async_commit
+tidb_enable_auto_analyze
+tidb_enable_mutation_checker
+tidb_mem_oom_action
+tidb_pessimistic_txn_fair_locking
+tidb_row_format_version
+tidb_txn_assertion_level
+set global tidb_enable_async_commit = default;
+set global tidb_enable_1pc = default;
+set global tidb_mem_oom_action = default;
+set global tidb_enable_auto_analyze = default;
+set global tidb_row_format_version = default;
+set global tidb_txn_assertion_level = default;
+set global tidb_enable_mutation_checker = default;
+set global tidb_pessimistic_txn_fair_locking = default;
+select a.VARIABLE_NAME from information_schema.VARIABLES_INFO as a, mysql.GLOBAL_VARIABLES as b where a.VARIABLE_NAME = b.VARIABLE_NAME and a.DEFAULT_VALUE = b.VARIABLE_VALUE and a.CURRENT_VALUE = b.VARIABLE_VALUE and a.variable_name in ('tidb_enable_async_commit','tidb_enable_1pc', 'tidb_mem_oom_action', 'tidb_enable_auto_analyze', 'tidb_row_format_version', 'tidb_txn_assertion_level', 'tidb_enable_mutation_checker', 'tidb_pessimistic_txn_fair_locking') order by VARIABLE_NAME;
+VARIABLE_NAME
+tidb_enable_1pc
+tidb_enable_async_commit
+tidb_enable_auto_analyze
+tidb_enable_mutation_checker
+tidb_mem_oom_action
+tidb_pessimistic_txn_fair_locking
+tidb_row_format_version
+tidb_txn_assertion_level

tests/integrationtest/t/executor/infoschema_reader.test

@@ -239,3 +239,15 @@ SELECT * FROM information_schema.user_privileges WHERE grantee="'usageuser'@'%'"
 
 connection default;
 disconnect conn1;
+
+# test information_schema.VARIABLES_INFO DEFAULT_VALUE
+select VARIABLE_NAME from information_schema.VARIABLES_INFO where DEFAULT_VALUE = CURRENT_VALUE and variable_name in ('tidb_enable_async_commit','tidb_enable_1pc', 'tidb_mem_oom_action', 'tidb_enable_auto_analyze', 'tidb_row_format_version', 'tidb_txn_assertion_level', 'tidb_enable_mutation_checker', 'tidb_pessimistic_txn_fair_locking') order by VARIABLE_NAME;
+set global tidb_enable_async_commit = default;
+set global tidb_enable_1pc = default;
+set global tidb_mem_oom_action = default;
+set global tidb_enable_auto_analyze = default;
+set global tidb_row_format_version = default;
+set global tidb_txn_assertion_level = default;
+set global tidb_enable_mutation_checker = default;
+set global tidb_pessimistic_txn_fair_locking = default;
+select a.VARIABLE_NAME from information_schema.VARIABLES_INFO as a, mysql.GLOBAL_VARIABLES as b where a.VARIABLE_NAME = b.VARIABLE_NAME and a.DEFAULT_VALUE = b.VARIABLE_VALUE and a.CURRENT_VALUE = b.VARIABLE_VALUE and a.variable_name in ('tidb_enable_async_commit','tidb_enable_1pc', 'tidb_mem_oom_action', 'tidb_enable_auto_analyze', 'tidb_row_format_version', 'tidb_txn_assertion_level', 'tidb_enable_mutation_checker', 'tidb_pessimistic_txn_fair_locking') order by VARIABLE_NAME;