planner: Revert tidb_allow_mpp modification for downgrade compatibility and add warnings for enforce mpp. (#25302)

config/config.go

@@ -424,6 +424,7 @@ type Performance struct {
 	MemProfileInterval    string  `toml:"mem-profile-interval" json:"mem-profile-interval"`
 	IndexUsageSyncLease   string  `toml:"index-usage-sync-lease" json:"index-usage-sync-lease"`
 	GOGC                  int     `toml:"gogc" json:"gogc"`
+	EnforceMPP            bool    `toml:"enforce-mpp" json:"enforce-mpp"`
 }
 
 // PlanCache is the PlanCache section of the config.
@@ -623,6 +624,7 @@ var defaultConf = Config{
 		// TODO: set indexUsageSyncLease to 60s.
 		IndexUsageSyncLease: "0s",
 		GOGC:                100,
+		EnforceMPP:          false,
 	},
 	ProxyProtocol: ProxyProtocol{
 		Networks:      "",

executor/tiflash_test.go

@@ -300,7 +300,7 @@ func (s *tiflashTestSuite) TestTiFlashPartitionTableShuffledHashJoin(c *C) {
 		tk.MustExec(fmt.Sprintf("analyze table %v", tbl))
 	}
 
-	tk.MustExec("SET tidb_allow_mpp=2")
+	tk.MustExec("SET tidb_enforce_mpp=1")
 	tk.MustExec("SET tidb_opt_broadcast_join=0")
 	tk.MustExec("SET tidb_broadcast_join_threshold_count=0")
 	tk.MustExec("SET tidb_broadcast_join_threshold_size=0")
@@ -378,7 +378,7 @@ func (s *tiflashTestSuite) TestTiFlashPartitionTableReader(c *C) {
 		tk.MustExec(fmt.Sprintf("insert into %v values %v", tbl, strings.Join(vals, ", ")))
 	}
 
-	tk.MustExec("SET tidb_allow_mpp=2")
+	tk.MustExec("SET tidb_enforce_mpp=1")
 	tk.MustExec("set @@session.tidb_isolation_read_engines='tiflash'")
 	for i := 0; i < 100; i++ {
 		l, r := rand.Intn(400), rand.Intn(400)
@@ -742,7 +742,7 @@ func (s *tiflashTestSuite) TestTiFlashPartitionTableShuffledHashAggregation(c *C
 		tk.MustExec(fmt.Sprintf("analyze table %v", tbl))
 	}
 	tk.MustExec("set @@session.tidb_isolation_read_engines='tiflash'")
-	tk.MustExec("set @@session.tidb_allow_mpp=2")
+	tk.MustExec("set @@session.tidb_enforce_mpp=1")
 	// mock executor does not support use outer table as build side for outer join, so need to
 	// force the inner table as build side
 	tk.MustExec("set tidb_opt_mpp_outer_join_fixed_build_side=1")
@@ -814,7 +814,7 @@ func (s *tiflashTestSuite) TestTiFlashPartitionTableBroadcastJoin(c *C) {
 		tk.MustExec(fmt.Sprintf("analyze table %v", tbl))
 	}
 	tk.MustExec("set @@session.tidb_isolation_read_engines='tiflash'")
-	tk.MustExec("set @@session.tidb_allow_mpp=2")
+	tk.MustExec("set @@session.tidb_enforce_mpp=1")
 	tk.MustExec("set @@session.tidb_opt_broadcast_join=ON")
 	// mock executor does not support use outer table as build side for outer join, so need to
 	// force the inner table as build side

planner/core/enforce_mpp_test.go

@@ -0,0 +1,299 @@
+// Copyright 2019 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package core_test
+
+import (
+	"strings"
+
+	. "github.com/pingcap/check"
+	"github.com/pingcap/parser/model"
+	"github.com/pingcap/tidb/domain"
+	"github.com/pingcap/tidb/kv"
+	"github.com/pingcap/tidb/util/collate"
+	"github.com/pingcap/tidb/util/testkit"
+	"github.com/pingcap/tidb/util/testutil"
+)
+
+var _ = SerialSuites(&testEnforceMPPSuite{})
+
+type testEnforceMPPSuite struct {
+	testData testutil.TestData
+	store    kv.Storage
+	dom      *domain.Domain
+}
+
+func (s *testEnforceMPPSuite) SetUpSuite(c *C) {
+	var err error
+	s.testData, err = testutil.LoadTestSuiteData("testdata", "enforce_mpp_suite")
+	c.Assert(err, IsNil)
+}
+
+func (s *testEnforceMPPSuite) TearDownSuite(c *C) {
+	c.Assert(s.testData.GenerateOutputIfNeeded(), IsNil)
+}
+
+func (s *testEnforceMPPSuite) SetUpTest(c *C) {
+	var err error
+	s.store, s.dom, err = newStoreWithBootstrap()
+	c.Assert(err, IsNil)
+}
+
+func (s *testEnforceMPPSuite) TearDownTest(c *C) {
+	s.dom.Close()
+	err := s.store.Close()
+	c.Assert(err, IsNil)
+}
+
+func (s *testEnforceMPPSuite) TestSetVariables(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	// test value limit of tidb_opt_tiflash_concurrency_factor
+	err := tk.ExecToErr("set @@tidb_opt_tiflash_concurrency_factor = 0")
+	c.Assert(err, NotNil)
+	c.Assert(err.Error(), Equals, `[variable:1231]Variable 'tidb_opt_tiflash_concurrency_factor' can't be set to the value of '0'`)
+
+	// test set tidb_enforce_mpp when tidb_allow_mpp=false;
+	err = tk.ExecToErr("set @@tidb_allow_mpp = 0; set @@tidb_enforce_mpp = 1;")
+	c.Assert(err, NotNil)
+	c.Assert(err.Error(), Equals, `[variable:1231]Variable 'tidb_enforce_mpp' can't be set to the value of '1' but tidb_allow_mpp is 0, please activate tidb_allow_mpp at first.'`)
+
+	err = tk.ExecToErr("set @@tidb_allow_mpp = 1; set @@tidb_enforce_mpp = 1;")
+	c.Assert(err, IsNil)
+
+	err = tk.ExecToErr("set @@tidb_allow_mpp = 0;")
+	c.Assert(err, IsNil)
+}
+
+func (s *testEnforceMPPSuite) TestEnforceMPP(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	// test query
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int, b int)")
+	tk.MustExec("create index idx on t(a)")
+
+	// Create virtual tiflash replica info.
+	dom := domain.GetDomain(tk.Se)
+	is := dom.InfoSchema()
+	db, exists := is.SchemaByName(model.NewCIStr("test"))
+	c.Assert(exists, IsTrue)
+	for _, tblInfo := range db.Tables {
+		if tblInfo.Name.L == "t" {
+			tblInfo.TiFlashReplica = &model.TiFlashReplicaInfo{
+				Count:     1,
+				Available: true,
+			}
+		}
+	}
+
+	var input []string
+	var output []struct {
+		SQL  string
+		Plan []string
+		Warn []string
+	}
+	s.testData.GetTestCases(c, &input, &output)
+	for i, tt := range input {
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+		})
+		if strings.HasPrefix(tt, "set") {
+			tk.MustExec(tt)
+			continue
+		}
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+			output[i].Plan = s.testData.ConvertRowsToStrings(tk.MustQuery(tt).Rows())
+			output[i].Warn = s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings())
+		})
+		res := tk.MustQuery(tt)
+		res.Check(testkit.Rows(output[i].Plan...))
+		c.Assert(s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings()), DeepEquals, output[i].Warn)
+	}
+}
+
+// general cases.
+func (s *testEnforceMPPSuite) TestEnforceMPPWarning1(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	// test query
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int, b int as (a+1), c time)")
+	tk.MustExec("create index idx on t(a)")
+
+	var input []string
+	var output []struct {
+		SQL  string
+		Plan []string
+		Warn []string
+	}
+	s.testData.GetTestCases(c, &input, &output)
+	for i, tt := range input {
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+		})
+		if strings.HasPrefix(tt, "set") {
+			tk.MustExec(tt)
+			continue
+		}
+		if strings.HasPrefix(tt, "cmd: create-replica") {
+			// Create virtual tiflash replica info.
+			dom := domain.GetDomain(tk.Se)
+			is := dom.InfoSchema()
+			db, exists := is.SchemaByName(model.NewCIStr("test"))
+			c.Assert(exists, IsTrue)
+			for _, tblInfo := range db.Tables {
+				if tblInfo.Name.L == "t" {
+					tblInfo.TiFlashReplica = &model.TiFlashReplicaInfo{
+						Count:     1,
+						Available: false,
+					}
+				}
+			}
+			continue
+		}
+		if strings.HasPrefix(tt, "cmd: enable-replica") {
+			// Create virtual tiflash replica info.
+			dom := domain.GetDomain(tk.Se)
+			is := dom.InfoSchema()
+			db, exists := is.SchemaByName(model.NewCIStr("test"))
+			c.Assert(exists, IsTrue)
+			for _, tblInfo := range db.Tables {
+				if tblInfo.Name.L == "t" {
+					tblInfo.TiFlashReplica = &model.TiFlashReplicaInfo{
+						Count:     1,
+						Available: true,
+					}
+				}
+			}
+			continue
+		}
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+			output[i].Plan = s.testData.ConvertRowsToStrings(tk.MustQuery(tt).Rows())
+			output[i].Warn = s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings())
+		})
+		res := tk.MustQuery(tt)
+		res.Check(testkit.Rows(output[i].Plan...))
+		c.Assert(s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings()), DeepEquals, output[i].Warn)
+	}
+}
+
+// partition table.
+func (s *testEnforceMPPSuite) TestEnforceMPPWarning2(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	// test query
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("CREATE TABLE t (a int, b char(20)) PARTITION BY HASH(a)")
+
+	// Create virtual tiflash replica info.
+	dom := domain.GetDomain(tk.Se)
+	is := dom.InfoSchema()
+	db, exists := is.SchemaByName(model.NewCIStr("test"))
+	c.Assert(exists, IsTrue)
+	for _, tblInfo := range db.Tables {
+		if tblInfo.Name.L == "t" {
+			tblInfo.TiFlashReplica = &model.TiFlashReplicaInfo{
+				Count:     1,
+				Available: true,
+			}
+		}
+	}
+
+	var input []string
+	var output []struct {
+		SQL  string
+		Plan []string
+		Warn []string
+	}
+	s.testData.GetTestCases(c, &input, &output)
+	for i, tt := range input {
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+		})
+		if strings.HasPrefix(tt, "set") {
+			tk.MustExec(tt)
+			continue
+		}
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+			output[i].Plan = s.testData.ConvertRowsToStrings(tk.MustQuery(tt).Rows())
+			output[i].Warn = s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings())
+		})
+		res := tk.MustQuery(tt)
+		res.Check(testkit.Rows(output[i].Plan...))
+		c.Assert(s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings()), DeepEquals, output[i].Warn)
+	}
+}
+
+// new collation.
+func (s *testEnforceMPPSuite) TestEnforceMPPWarning3(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	// test query
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("CREATE TABLE t (a int, b char(20))")
+
+	// Create virtual tiflash replica info.
+	dom := domain.GetDomain(tk.Se)
+	is := dom.InfoSchema()
+	db, exists := is.SchemaByName(model.NewCIStr("test"))
+	c.Assert(exists, IsTrue)
+	for _, tblInfo := range db.Tables {
+		if tblInfo.Name.L == "t" {
+			tblInfo.TiFlashReplica = &model.TiFlashReplicaInfo{
+				Count:     1,
+				Available: true,
+			}
+		}
+	}
+
+	var input []string
+	var output []struct {
+		SQL  string
+		Plan []string
+		Warn []string
+	}
+	s.testData.GetTestCases(c, &input, &output)
+	for i, tt := range input {
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+		})
+		if strings.HasPrefix(tt, "set") || strings.HasPrefix(tt, "UPDATE") {
+			tk.MustExec(tt)
+			continue
+		}
+		if strings.HasPrefix(tt, "cmd: enable-new-collation") {
+			collate.SetNewCollationEnabledForTest(true)
+			continue
+		}
+		if strings.HasPrefix(tt, "cmd: disable-new-collation") {
+			collate.SetNewCollationEnabledForTest(false)
+			continue
+		}
+		s.testData.OnRecord(func() {
+			output[i].SQL = tt
+			output[i].Plan = s.testData.ConvertRowsToStrings(tk.MustQuery(tt).Rows())
+			output[i].Warn = s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings())
+		})
+		res := tk.MustQuery(tt)
+		res.Check(testkit.Rows(output[i].Plan...))
+		c.Assert(s.testData.ConvertSQLWarnToStrings(tk.Se.GetSessionVars().StmtCtx.GetWarnings()), DeepEquals, output[i].Warn)
+	}
+}