variables: add concurrent DDL switch (#35028)

ref #32031
pingcap · Jun 6, 2022 · 7ffab33 · 7ffab33
1 parent eca9f2d
commit 7ffab33
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Showing 3 changed files with 17 additions and 0 deletions.
diff --git a/expression/integration_serial_test.go b/expression/integration_serial_test.go
@@ -3747,6 +3747,13 @@ func TestSetVariables(t *testing.T) {
  _, err = tk.Exec("set @@global.max_prepared_stmt_count='';")
  require.Error(t, err)
  require.Error(t, err, variable.ErrWrongTypeForVar.GenWithStackByArgs("max_prepared_stmt_count").Error())
+
+ tk.MustQuery("select @@global.tidb_enable_concurrent_ddl").Check(testkit.Rows("1"))
+ require.True(t, variable.EnableConcurrentDDL.Load())
+ tk.MustExec("set @@global.tidb_enable_concurrent_ddl=0")
+ tk.MustQuery("select @@global.tidb_enable_concurrent_ddl").Check(testkit.Rows("0"))
+ require.False(t, variable.EnableConcurrentDDL.Load())
+ testkit.NewTestKit(t, store).MustQuery("select @@global.tidb_enable_concurrent_ddl").Check(testkit.Rows("0"))
 }
 
 func TestPreparePlanCache(t *testing.T) {

diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
@@ -798,6 +798,12 @@ var defaultSysVars = []*SysVar{
  return err
  },
  },
+ {Scope: ScopeGlobal, Name: TiDBEnableConcurrentDDL, Value: BoolToOnOff(DefTiDBEnableConcurrentDDL), Type: TypeBool, SetGlobal: func(s *SessionVars, val string) error {
+ EnableConcurrentDDL.Store(TiDBOptOn(val))
+ return nil
+ }, GetGlobal: func(s *SessionVars) (string, error) {
+ return BoolToOnOff(EnableConcurrentDDL.Load()), nil
+ }},
 
  /* The system variables below have GLOBAL and SESSION scope */
  {Scope: ScopeGlobal | ScopeSession, Name: SQLSelectLimit, Value: "18446744073709551615", Type: TypeUnsigned, MinValue: 0, MaxValue: math.MaxUint64, SetSession: func(s *SessionVars, val string) error {

diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
@@ -704,6 +704,8 @@ const (
  // TiDBMaxAutoAnalyzeTime is the max time that auto analyze can run. If auto analyze runs longer than the value, it
  // will be killed. 0 indicates that there is no time limit.
  TiDBMaxAutoAnalyzeTime = "tidb_max_auto_analyze_time"
+ // TiDBEnableConcurrentDDL indicates whether to enable the new DDL framework.
+ TiDBEnableConcurrentDDL = "tidb_enable_concurrent_ddl"
 )
 
 // TiDB intentional limits
@@ -892,6 +894,7 @@ const (
  DefTiDBEnablePrepPlanCache = true
  DefTiDBPrepPlanCacheSize = 100
  DefTiDBPrepPlanCacheMemoryGuardRatio = 0.1
+ DefTiDBEnableConcurrentDDL = true
 )
 
 // Process global variables.
@@ -939,6 +942,7 @@ var (
  EnablePreparedPlanCache = atomic.NewBool(DefTiDBEnablePrepPlanCache)
  PreparedPlanCacheSize = atomic.NewUint64(DefTiDBPrepPlanCacheSize)
  PreparedPlanCacheMemoryGuardRatio = atomic.NewFloat64(DefTiDBPrepPlanCacheMemoryGuardRatio)
+ EnableConcurrentDDL = atomic.NewBool(DefTiDBEnableConcurrentDDL)
 )
 
 var (