domain,infoschema: put the @@tidb_schema_cache_size variable into effect (#53424)

ref pingcap/tidb#50959

pkg/executor/BUILD.bazel

@@ -454,6 +454,7 @@ go_test(
         "//pkg/util/syncutil",
         "//pkg/util/tableutil",
         "//pkg/util/topsql/state",
+        "@com_github_docker_go_units//:go-units",
         "@com_github_gorilla_mux//:mux",
         "@com_github_hashicorp_go_version//:go-version",
         "@com_github_pingcap_errors//:errors",

pkg/executor/show_stats_test.go

@@ -19,6 +19,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/docker/go-units"
 	"github.com/pingcap/tidb/pkg/domain/infosync"
 	"github.com/pingcap/tidb/pkg/parser/model"
 	"github.com/pingcap/tidb/pkg/sessionctx/variable"
@@ -292,7 +293,7 @@ func TestShowStatusSnapshot(t *testing.T) {
 	UPDATE variable_value = '%[2]s', comment = '%[3]s'`, safePointName, safePointValue, safePointComment)
 	tk.MustExec(updateSafePoint)
 
-	for _, cacheSize := range []int{1024, 0} {
+	for _, cacheSize := range []int{units.GiB, 0} {
 		tk.MustExec("set @@global.tidb_schema_cache_size = ?", cacheSize)
 		tk.MustExec("create table t (a int);")
 		snapshotTime := time.Now()

pkg/executor/stale_txn_test.go

@@ -20,6 +20,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/docker/go-units"
 	"github.com/pingcap/errors"
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/tidb/pkg/config"
@@ -893,7 +894,7 @@ func TestSetTransactionInfoSchema(t *testing.T) {
 	UPDATE variable_value = '%[2]s', comment = '%[3]s'`, safePointName, safePointValue, safePointComment)
 	tk.MustExec(updateSafePoint)
 
-	for _, cacheSize := range []int{1024, 0} {
+	for _, cacheSize := range []int{units.GiB, 0} {
 		tk.MustExec("set @@global.tidb_schema_cache_size = ?", cacheSize)
 		testSetTransactionInfoSchema(t, tk)
 	}

pkg/infoschema/builder.go

@@ -977,14 +977,19 @@ func RegisterVirtualTable(dbInfo *model.DBInfo, tableFromMeta tableFromMetaFunc)
 
 // NewBuilder creates a new Builder with a Handle.
 func NewBuilder(r autoid.Requirement, factory func() (pools.Resource, error), infoData *Data) *Builder {
-	return &Builder{
-		enableV2:     variable.SchemaCacheSize.Load() > 0,
+	builder := &Builder{
 		Requirement:  r,
 		infoschemaV2: NewInfoSchemaV2(r, infoData),
 		dirtyDB:      make(map[string]bool),
 		factory:      factory,
 		infoData:     infoData,
 	}
+	schemaCacheSize := variable.SchemaCacheSize.Load()
+	if schemaCacheSize > 0 {
+		infoData.tableCache.SetCapacity(uint64(schemaCacheSize))
+		builder.enableV2 = true
+	}
+	return builder
 }
 
 func tableBucketIdx(tableID int64) int {

pkg/infoschema/infoschema_v2.go

@@ -162,6 +162,11 @@ func NewData() *Data {
 	return ret
 }
 
+// CacheCapacity is exported for testing.
+func (isd *Data) CacheCapacity() uint64 {
+	return isd.tableCache.Capacity()
+}
+
 func (isd *Data) add(item tableItem, tbl table.Table) {
 	isd.byID.Set(item)
 	isd.byName.Set(item)
@@ -424,6 +429,7 @@ func (is *infoschemaV2) SchemaTableInfos(schema model.CIStr) []*model.TableInfo
 		return getTableInfoList(tables)
 	}
 
+retry:
 	dbInfo, ok := is.SchemaByName(schema)
 	if !ok {
 		return nil
@@ -438,6 +444,13 @@ func (is *infoschemaV2) SchemaTableInfos(schema model.CIStr) []*model.TableInfo
 		if meta.ErrDBNotExists.Equal(err) {
 			return nil
 		}
+		// Flashback statement could cause such kind of error.
+		// In theory that error should be handled in the lower layer, like client-go.
+		// But it's not done, so we retry here.
+		if strings.Contains(err.Error(), "in flashback progress") {
+			time.Sleep(200 * time.Millisecond)
+			goto retry
+		}
 		// TODO: error could happen, so do not panic!
 		panic(err)
 	}
@@ -650,6 +663,7 @@ retry:
 func loadTableInfo(r autoid.Requirement, infoData *Data, tblID, dbID int64, ts uint64, schemaVersion int64) (table.Table, error) {
 	// Try to avoid repeated concurrency loading.
 	res, err, _ := loadTableSF.Do(fmt.Sprintf("%d-%d-%d", dbID, tblID, schemaVersion), func() (any, error) {
+	retry:
 		snapshot := r.Store().GetSnapshot(kv.NewVersion(ts))
 		// Using the KV timeout read feature to address the issue of potential DDL lease expiration when
 		// the meta region leader is slow.
@@ -657,8 +671,15 @@ func loadTableInfo(r autoid.Requirement, infoData *Data, tblID, dbID int64, ts u
 		m := meta.NewSnapshotMeta(snapshot)
 
 		tblInfo, err := m.GetTable(dbID, tblID)
-
 		if err != nil {
+			// Flashback statement could cause such kind of error.
+			// In theory that error should be handled in the lower layer, like client-go.
+			// But it's not done, so we retry here.
+			if strings.Contains(err.Error(), "in flashback progress") {
+				time.Sleep(200 * time.Millisecond)
+				goto retry
+			}
+
 			// TODO load table panic!!!
 			panic(err)
 		}

pkg/infoschema/sieve.go

@@ -75,6 +75,12 @@ func (s *Sieve[K, V]) SetCapacity(capacity uint64) {
 	s.capacity = capacity
 }
 
+func (s *Sieve[K, V]) Capacity() uint64 {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.capacity
+}
+
 func (s *Sieve[K, V]) Set(key K, value V) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

pkg/infoschema/test/infoschemav2test/BUILD.bazel

@@ -8,11 +8,13 @@ go_test(
         "v2_test.go",
     ],
     flaky = True,
+    shard_count = 3,
     deps = [
         "//pkg/domain",
         "//pkg/infoschema",
         "//pkg/parser/auth",
         "//pkg/parser/model",
+        "//pkg/sessionctx/variable",
         "//pkg/table",
         "//pkg/testkit",
         "//pkg/testkit/testsetup",

pkg/infoschema/test/infoschemav2test/v2_test.go

@@ -15,12 +15,14 @@
 package infoschemav2test
 
 import (
+	"strconv"
 	"testing"
 
 	"github.com/pingcap/tidb/pkg/domain"
 	"github.com/pingcap/tidb/pkg/infoschema"
 	"github.com/pingcap/tidb/pkg/parser/auth"
 	"github.com/pingcap/tidb/pkg/parser/model"
+	"github.com/pingcap/tidb/pkg/sessionctx/variable"
 	"github.com/pingcap/tidb/pkg/table"
 	"github.com/pingcap/tidb/pkg/testkit"
 	"github.com/stretchr/testify/require"
@@ -147,3 +149,29 @@ PARTITION p5 VALUES LESS THAN (1980))`)
 	pid = pi.GetPartitionIDByName("p3")
 	require.Equal(t, pid, ntbl.Meta().ID)
 }
+
+func TestTiDBSchemaCacheSizeVariable(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomain(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	dom.Reload() // need this to trigger infoschema rebuild to reset capacity
+	is := dom.InfoSchema()
+	ok, raw := infoschema.IsV2(is)
+	if ok {
+		val := variable.SchemaCacheSize.Load()
+		tk.MustQuery("select @@global.tidb_schema_cache_size").CheckContain(strconv.FormatInt(val, 10))
+
+		// On start, the capacity might not be set correctly because infoschema have not load global variable yet.
+		// cap := raw.Data.CacheCapacity()
+		// require.Equal(t, cap, uint64(val))
+	}
+
+	tk.MustExec("set @@global.tidb_schema_cache_size = 32 * 1024 * 1024")
+	tk.MustQuery("select @@global.tidb_schema_cache_size").CheckContain("33554432")
+	require.Equal(t, variable.SchemaCacheSize.Load(), int64(33554432))
+	tk.MustExec("create table trigger_reload (id int)") // need to trigger infoschema rebuild to reset capacity
+	is = dom.InfoSchema()
+	ok, raw = infoschema.IsV2(is)
+	require.True(t, ok)
+	require.Equal(t, raw.Data.CacheCapacity(), uint64(33554432))
+}

pkg/testkit/testkit.go

@@ -120,7 +120,7 @@ func (tk *TestKit) RefreshSession() {
 
 	if intest.InTest {
 		if rand.Intn(10) >= 3 { // 70% chance to run infoschema v2
-			tk.MustExec("set @@global.tidb_schema_cache_size = 1024")
+			tk.MustExec("set @@global.tidb_schema_cache_size = 1024 * 1024 * 1024")
 		}
 	}