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statistics: move statsReader out of statistics/handle (#40790)
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ref #40624, ref #40791
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@xuyifangreeneyes
xuyifangreeneyes committed Jan 28, 2023
1 parent bca433f commit 187cafc
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Showing 6 changed files with 128 additions and 92 deletions.
1 change: 1 addition & 0 deletions statistics/BUILD.bazel
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ go_library(
"fmsketch.go",
"histogram.go",
"index.go",
"interact_with_storage.go",
"merge_worker.go",
"row_sampler.go",
"sample.go",
Expand Down
8 changes: 4 additions & 4 deletions statistics/handle/dump.go
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Original file line number Diff line number Diff line change
Expand Up @@ -263,7 +263,7 @@ func (h *Handle) tableHistoricalStatsToJSON(physicalID int64, snapshot uint64) (
}()

// get meta version
rows, _, err := reader.read("select distinct version from mysql.stats_meta_history where table_id = %? and version <= %? order by version desc limit 1", physicalID, snapshot)
rows, _, err := reader.Read("select distinct version from mysql.stats_meta_history where table_id = %? and version <= %? order by version desc limit 1", physicalID, snapshot)
if err != nil {
return nil, errors.AddStack(err)
}
Expand All @@ -272,14 +272,14 @@ func (h *Handle) tableHistoricalStatsToJSON(physicalID int64, snapshot uint64) (
}
statsMetaVersion := rows[0].GetInt64(0)
// get stats meta
rows, _, err = reader.read("select modify_count, count from mysql.stats_meta_history where table_id = %? and version = %?", physicalID, statsMetaVersion)
rows, _, err = reader.Read("select modify_count, count from mysql.stats_meta_history where table_id = %? and version = %?", physicalID, statsMetaVersion)
if err != nil {
return nil, errors.AddStack(err)
}
modifyCount, count := rows[0].GetInt64(0), rows[0].GetInt64(1)

// get stats version
rows, _, err = reader.read("select distinct version from mysql.stats_history where table_id = %? and version <= %? order by version desc limit 1", physicalID, snapshot)
rows, _, err = reader.Read("select distinct version from mysql.stats_history where table_id = %? and version <= %? order by version desc limit 1", physicalID, snapshot)
if err != nil {
return nil, errors.AddStack(err)
}
Expand All @@ -289,7 +289,7 @@ func (h *Handle) tableHistoricalStatsToJSON(physicalID int64, snapshot uint64) (
statsVersion := rows[0].GetInt64(0)

// get stats
rows, _, err = reader.read("select stats_data from mysql.stats_history where table_id = %? and version = %? order by seq_no", physicalID, statsVersion)
rows, _, err = reader.Read("select stats_data from mysql.stats_history where table_id = %? and version = %? order by seq_no", physicalID, statsVersion)
if err != nil {
return nil, errors.AddStack(err)
}
Expand Down
105 changes: 27 additions & 78 deletions statistics/handle/handle.go
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Original file line number Diff line number Diff line change
Expand Up @@ -1067,7 +1067,7 @@ func (h *Handle) LoadNeededHistograms() (err error) {
return nil
}

func (h *Handle) loadNeededColumnHistograms(reader *statsReader, col model.TableItemID, loadFMSketch bool) (err error) {
func (h *Handle) loadNeededColumnHistograms(reader *statistics.StatsReader, col model.TableItemID, loadFMSketch bool) (err error) {
oldCache := h.statsCache.Load().(statsCache)
tbl, ok := oldCache.Get(col.TableID)
if !ok {
Expand All @@ -1093,7 +1093,7 @@ func (h *Handle) loadNeededColumnHistograms(reader *statsReader, col model.Table
return errors.Trace(err)
}
}
rows, _, err := reader.read("select stats_ver from mysql.stats_histograms where is_index = 0 and table_id = %? and hist_id = %?", col.TableID, col.ID)
rows, _, err := reader.Read("select stats_ver from mysql.stats_histograms where is_index = 0 and table_id = %? and hist_id = %?", col.TableID, col.ID)
if err != nil {
return errors.Trace(err)
}
Expand Down Expand Up @@ -1134,7 +1134,7 @@ func (h *Handle) loadNeededColumnHistograms(reader *statsReader, col model.Table
return nil
}

func (h *Handle) loadNeededIndexHistograms(reader *statsReader, idx model.TableItemID, loadFMSketch bool) (err error) {
func (h *Handle) loadNeededIndexHistograms(reader *statistics.StatsReader, idx model.TableItemID, loadFMSketch bool) (err error) {
oldCache := h.statsCache.Load().(statsCache)
tbl, ok := oldCache.Get(idx.TableID)
if !ok {
Expand All @@ -1160,7 +1160,7 @@ func (h *Handle) loadNeededIndexHistograms(reader *statsReader, idx model.TableI
return errors.Trace(err)
}
}
rows, _, err := reader.read("select stats_ver from mysql.stats_histograms where is_index = 1 and table_id = %? and hist_id = %?", idx.TableID, idx.ID)
rows, _, err := reader.Read("select stats_ver from mysql.stats_histograms where is_index = 1 and table_id = %? and hist_id = %?", idx.TableID, idx.ID)
if err != nil {
return errors.Trace(err)
}
Expand Down Expand Up @@ -1214,12 +1214,12 @@ func (h *Handle) FlushStats() {
}
}

func (h *Handle) cmSketchAndTopNFromStorage(reader *statsReader, tblID int64, isIndex, histID int64) (_ *statistics.CMSketch, _ *statistics.TopN, err error) {
topNRows, _, err := reader.read("select HIGH_PRIORITY value, count from mysql.stats_top_n where table_id = %? and is_index = %? and hist_id = %?", tblID, isIndex, histID)
func (h *Handle) cmSketchAndTopNFromStorage(reader *statistics.StatsReader, tblID int64, isIndex, histID int64) (_ *statistics.CMSketch, _ *statistics.TopN, err error) {
topNRows, _, err := reader.Read("select HIGH_PRIORITY value, count from mysql.stats_top_n where table_id = %? and is_index = %? and hist_id = %?", tblID, isIndex, histID)
if err != nil {
return nil, nil, err
}
rows, _, err := reader.read("select cm_sketch from mysql.stats_histograms where table_id = %? and is_index = %? and hist_id = %?", tblID, isIndex, histID)
rows, _, err := reader.Read("select cm_sketch from mysql.stats_histograms where table_id = %? and is_index = %? and hist_id = %?", tblID, isIndex, histID)
if err != nil {
return nil, nil, err
}
Expand All @@ -1229,15 +1229,15 @@ func (h *Handle) cmSketchAndTopNFromStorage(reader *statsReader, tblID int64, is
return statistics.DecodeCMSketchAndTopN(rows[0].GetBytes(0), topNRows)
}

func (h *Handle) fmSketchFromStorage(reader *statsReader, tblID int64, isIndex, histID int64) (_ *statistics.FMSketch, err error) {
rows, _, err := reader.read("select value from mysql.stats_fm_sketch where table_id = %? and is_index = %? and hist_id = %?", tblID, isIndex, histID)
func (h *Handle) fmSketchFromStorage(reader *statistics.StatsReader, tblID int64, isIndex, histID int64) (_ *statistics.FMSketch, err error) {
rows, _, err := reader.Read("select value from mysql.stats_fm_sketch where table_id = %? and is_index = %? and hist_id = %?", tblID, isIndex, histID)
if err != nil || len(rows) == 0 {
return nil, err
}
return statistics.DecodeFMSketch(rows[0].GetBytes(0))
}

func (h *Handle) indexStatsFromStorage(reader *statsReader, row chunk.Row, table *statistics.Table, tableInfo *model.TableInfo) error {
func (h *Handle) indexStatsFromStorage(reader *statistics.StatsReader, row chunk.Row, table *statistics.Table, tableInfo *model.TableInfo) error {
histID := row.GetInt64(2)
distinct := row.GetInt64(3)
histVer := row.GetUint64(4)
Expand All @@ -1247,7 +1247,7 @@ func (h *Handle) indexStatsFromStorage(reader *statsReader, row chunk.Row, table
errorRate := statistics.ErrorRate{}
flag := row.GetInt64(8)
lastAnalyzePos := row.GetDatum(10, types.NewFieldType(mysql.TypeBlob))
if statistics.IsAnalyzed(flag) && !reader.isHistory() {
if statistics.IsAnalyzed(flag) && !reader.IsHistory() {
h.mu.rateMap.clear(table.PhysicalID, histID, true)
} else if idx != nil {
errorRate = idx.ErrorRate
Expand Down Expand Up @@ -1295,7 +1295,7 @@ func (h *Handle) indexStatsFromStorage(reader *statsReader, row chunk.Row, table
return nil
}

func (h *Handle) columnStatsFromStorage(reader *statsReader, row chunk.Row, table *statistics.Table, tableInfo *model.TableInfo, loadAll bool) error {
func (h *Handle) columnStatsFromStorage(reader *statistics.StatsReader, row chunk.Row, table *statistics.Table, tableInfo *model.TableInfo, loadAll bool) error {
histID := row.GetInt64(2)
distinct := row.GetInt64(3)
histVer := row.GetUint64(4)
Expand All @@ -1307,7 +1307,7 @@ func (h *Handle) columnStatsFromStorage(reader *statsReader, row chunk.Row, tabl
col := table.Columns[histID]
errorRate := statistics.ErrorRate{}
flag := row.GetInt64(8)
if statistics.IsAnalyzed(flag) && !reader.isHistory() {
if statistics.IsAnalyzed(flag) && !reader.IsHistory() {
h.mu.rateMap.clear(table.PhysicalID, histID, false)
} else if col != nil {
errorRate = col.ErrorRate
Expand Down Expand Up @@ -1439,14 +1439,14 @@ func (h *Handle) TableStatsFromStorage(tableInfo *model.TableInfo, physicalID in
}
table.Pseudo = false

rows, _, err := reader.read("select modify_count, count from mysql.stats_meta where table_id = %?", physicalID)
rows, _, err := reader.Read("select modify_count, count from mysql.stats_meta where table_id = %?", physicalID)
if err != nil || len(rows) == 0 {
return nil, err
}
table.ModifyCount = rows[0].GetInt64(0)
table.Count = rows[0].GetInt64(1)

rows, _, err = reader.read("select table_id, is_index, hist_id, distinct_count, version, null_count, tot_col_size, stats_ver, flag, correlation, last_analyze_pos from mysql.stats_histograms where table_id = %?", physicalID)
rows, _, err = reader.Read("select table_id, is_index, hist_id, distinct_count, version, null_count, tot_col_size, stats_ver, flag, correlation, last_analyze_pos from mysql.stats_histograms where table_id = %?", physicalID)
// Check deleted table.
if err != nil || len(rows) == 0 {
return nil, nil
Expand All @@ -1464,7 +1464,7 @@ func (h *Handle) TableStatsFromStorage(tableInfo *model.TableInfo, physicalID in
return h.extendedStatsFromStorage(reader, table, physicalID, loadAll)
}

func (h *Handle) extendedStatsFromStorage(reader *statsReader, table *statistics.Table, physicalID int64, loadAll bool) (*statistics.Table, error) {
func (h *Handle) extendedStatsFromStorage(reader *statistics.StatsReader, table *statistics.Table, physicalID int64, loadAll bool) (*statistics.Table, error) {
failpoint.Inject("injectExtStatsLoadErr", func() {
failpoint.Return(nil, errors.New("gofail extendedStatsFromStorage error"))
})
Expand All @@ -1474,7 +1474,7 @@ func (h *Handle) extendedStatsFromStorage(reader *statsReader, table *statistics
} else {
table.ExtendedStats = statistics.NewExtendedStatsColl()
}
rows, _, err := reader.read("select name, status, type, column_ids, stats, version from mysql.stats_extended where table_id = %? and status in (%?, %?, %?) and version > %?", physicalID, StatsStatusInited, StatsStatusAnalyzed, StatsStatusDeleted, lastVersion)
rows, _, err := reader.Read("select name, status, type, column_ids, stats, version from mysql.stats_extended where table_id = %? and status in (%?, %?, %?) and version > %?", physicalID, StatsStatusInited, StatsStatusAnalyzed, StatsStatusDeleted, lastVersion)
if err != nil || len(rows) == 0 {
return table, nil
}
Expand Down Expand Up @@ -1525,7 +1525,7 @@ func (h *Handle) StatsMetaCountAndModifyCount(tableID int64) (int64, int64, erro
err = err1
}
}()
rows, _, err := reader.read("select count, modify_count from mysql.stats_meta where table_id = %?", tableID)
rows, _, err := reader.Read("select count, modify_count from mysql.stats_meta where table_id = %?", tableID)
if err != nil {
return 0, 0, err
}
Expand Down Expand Up @@ -1913,8 +1913,8 @@ func (h *Handle) SaveMetaToStorage(tableID, count, modifyCount int64, source str
return err
}

func (h *Handle) histogramFromStorage(reader *statsReader, tableID int64, colID int64, tp *types.FieldType, distinct int64, isIndex int, ver uint64, nullCount int64, totColSize int64, corr float64) (_ *statistics.Histogram, err error) {
rows, fields, err := reader.read("select count, repeats, lower_bound, upper_bound, ndv from mysql.stats_buckets where table_id = %? and is_index = %? and hist_id = %? order by bucket_id", tableID, isIndex, colID)
func (h *Handle) histogramFromStorage(reader *statistics.StatsReader, tableID int64, colID int64, tp *types.FieldType, distinct int64, isIndex int, ver uint64, nullCount int64, totColSize int64, corr float64) (_ *statistics.Histogram, err error) {
rows, fields, err := reader.Read("select count, repeats, lower_bound, upper_bound, ndv from mysql.stats_buckets where table_id = %? and is_index = %? and hist_id = %? order by bucket_id", tableID, isIndex, colID)
if err != nil {
return nil, errors.Trace(err)
}
Expand Down Expand Up @@ -1961,9 +1961,9 @@ func (h *Handle) histogramFromStorage(reader *statsReader, tableID int64, colID
return hg, nil
}

func (h *Handle) columnCountFromStorage(reader *statsReader, tableID, colID, statsVer int64) (int64, error) {
func (h *Handle) columnCountFromStorage(reader *statistics.StatsReader, tableID, colID, statsVer int64) (int64, error) {
count := int64(0)
rows, _, err := reader.read("select sum(count) from mysql.stats_buckets where table_id = %? and is_index = 0 and hist_id = %?", tableID, colID)
rows, _, err := reader.Read("select sum(count) from mysql.stats_buckets where table_id = %? and is_index = 0 and hist_id = %?", tableID, colID)
if err != nil {
return 0, errors.Trace(err)
}
Expand All @@ -1979,7 +1979,7 @@ func (h *Handle) columnCountFromStorage(reader *statsReader, tableID, colID, sta
// Before stats ver 2, histogram represents all data in this column.
// In stats ver 2, histogram + TopN represent all data in this column.
// So we need to add TopN total count here.
rows, _, err = reader.read("select sum(count) from mysql.stats_top_n where table_id = %? and is_index = 0 and hist_id = %?", tableID, colID)
rows, _, err = reader.Read("select sum(count) from mysql.stats_top_n where table_id = %? and is_index = 0 and hist_id = %?", tableID, colID)
if err != nil {
return 0, errors.Trace(err)
}
Expand Down Expand Up @@ -2014,26 +2014,7 @@ func (h *Handle) statsMetaByTableIDFromStorage(tableID int64, snapshot uint64) (
return
}

// statsReader is used for simplify code that needs to read system tables in different sqls
// but requires the same transactions.
type statsReader struct {
ctx sqlexec.RestrictedSQLExecutor
snapshot uint64
}

func (sr *statsReader) read(sql string, args ...interface{}) (rows []chunk.Row, fields []*ast.ResultField, err error) {
ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnStats)
if sr.snapshot > 0 {
return sr.ctx.ExecRestrictedSQL(ctx, []sqlexec.OptionFuncAlias{sqlexec.ExecOptionUseSessionPool, sqlexec.ExecOptionWithSnapshot(sr.snapshot)}, sql, args...)
}
return sr.ctx.ExecRestrictedSQL(ctx, []sqlexec.OptionFuncAlias{sqlexec.ExecOptionUseCurSession}, sql, args...)
}

func (sr *statsReader) isHistory() bool {
return sr.snapshot > 0
}

func (h *Handle) getGlobalStatsReader(snapshot uint64) (reader *statsReader, err error) {
func (h *Handle) getGlobalStatsReader(snapshot uint64) (reader *statistics.StatsReader, err error) {
h.mu.Lock()
defer func() {
if r := recover(); r != nil {
Expand All @@ -2043,44 +2024,12 @@ func (h *Handle) getGlobalStatsReader(snapshot uint64) (reader *statsReader, err
h.mu.Unlock()
}
}()
return h.getStatsReader(snapshot, h.mu.ctx.(sqlexec.RestrictedSQLExecutor))
return statistics.GetStatsReader(snapshot, h.mu.ctx.(sqlexec.RestrictedSQLExecutor))
}

func (h *Handle) releaseGlobalStatsReader(reader *statsReader) error {
func (h *Handle) releaseGlobalStatsReader(reader *statistics.StatsReader) error {
defer h.mu.Unlock()
return h.releaseStatsReader(reader, h.mu.ctx.(sqlexec.RestrictedSQLExecutor))
}

func (h *Handle) getStatsReader(snapshot uint64, exec sqlexec.RestrictedSQLExecutor) (reader *statsReader, err error) {
failpoint.Inject("mockGetStatsReaderFail", func(val failpoint.Value) {
if val.(bool) {
failpoint.Return(nil, errors.New("gofail genStatsReader error"))
}
})
if snapshot > 0 {
return &statsReader{ctx: exec, snapshot: snapshot}, nil
}
defer func() {
if r := recover(); r != nil {
err = fmt.Errorf("getStatsReader panic %v", r)
}
}()
ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnStats)
failpoint.Inject("mockGetStatsReaderPanic", nil)
_, err = exec.(sqlexec.SQLExecutor).ExecuteInternal(ctx, "begin")
if err != nil {
return nil, err
}
return &statsReader{ctx: exec}, nil
}

func (h *Handle) releaseStatsReader(reader *statsReader, exec sqlexec.RestrictedSQLExecutor) error {
if reader.snapshot > 0 {
return nil
}
ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnStats)
_, err := exec.(sqlexec.SQLExecutor).ExecuteInternal(ctx, "commit")
return err
return reader.Close()
}

const (
Expand Down
12 changes: 6 additions & 6 deletions statistics/handle/handle_hist.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -177,7 +177,7 @@ var errExit = errors.New("Stop loading since domain is closed")

// StatsReaderContext exported for testing
type StatsReaderContext struct {
reader *statsReader
reader *statistics.StatsReader
createdTime time.Time
}

Expand All @@ -188,7 +188,7 @@ func (h *Handle) SubLoadWorker(ctx sessionctx.Context, exit chan struct{}, exitW
exitWg.Done()
logutil.BgLogger().Info("SubLoadWorker exited.")
if readerCtx.reader != nil {
err := h.releaseStatsReader(readerCtx.reader, ctx.(sqlexec.RestrictedSQLExecutor))
err := readerCtx.reader.Close()
if err != nil {
logutil.BgLogger().Error("Fail to release stats loader: ", zap.Error(err))
}
Expand Down Expand Up @@ -295,13 +295,13 @@ func (h *Handle) handleOneItemTask(task *NeededItemTask, readerCtx *StatsReaderC
func (h *Handle) loadFreshStatsReader(readerCtx *StatsReaderContext, ctx sqlexec.RestrictedSQLExecutor) {
if readerCtx.reader == nil || readerCtx.createdTime.Add(h.Lease()).Before(time.Now()) {
if readerCtx.reader != nil {
err := h.releaseStatsReader(readerCtx.reader, ctx)
err := readerCtx.reader.Close()
if err != nil {
logutil.BgLogger().Warn("Fail to release stats loader: ", zap.Error(err))
}
}
for {
newReader, err := h.getStatsReader(0, ctx)
newReader, err := statistics.GetStatsReader(0, ctx)
if err != nil {
logutil.BgLogger().Error("Fail to new stats loader, retry after a while.", zap.Error(err))
time.Sleep(h.Lease() / 10)
Expand All @@ -317,7 +317,7 @@ func (h *Handle) loadFreshStatsReader(readerCtx *StatsReaderContext, ctx sqlexec
}

// readStatsForOneItem reads hist for one column/index, TODO load data via kv-get asynchronously
func (h *Handle) readStatsForOneItem(item model.TableItemID, w *statsWrapper, reader *statsReader) (*statsWrapper, error) {
func (h *Handle) readStatsForOneItem(item model.TableItemID, w *statsWrapper, reader *statistics.StatsReader) (*statsWrapper, error) {
failpoint.Inject("mockReadStatsForOnePanic", nil)
failpoint.Inject("mockReadStatsForOneFail", func(val failpoint.Value) {
if val.(bool) {
Expand Down Expand Up @@ -357,7 +357,7 @@ func (h *Handle) readStatsForOneItem(item model.TableItemID, w *statsWrapper, re
return nil, errors.Trace(err)
}
}
rows, _, err := reader.read("select stats_ver from mysql.stats_histograms where table_id = %? and hist_id = %? and is_index = %?", item.TableID, item.ID, int(isIndexFlag))
rows, _, err := reader.Read("select stats_ver from mysql.stats_histograms where table_id = %? and hist_id = %? and is_index = %?", item.TableID, item.ID, int(isIndexFlag))
if err != nil {
return nil, errors.Trace(err)
}
Expand Down
8 changes: 4 additions & 4 deletions statistics/handle/handle_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -622,16 +622,16 @@ func TestLoadStats(t *testing.T) {
require.True(t, idx.IsFullLoad())

// Following test tests whether the LoadNeededHistograms would panic.
require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/statistics/handle/mockGetStatsReaderFail", `return(true)`))
require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/statistics/mockGetStatsReaderFail", `return(true)`))
err = h.LoadNeededHistograms()
require.Error(t, err)
require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/statistics/handle/mockGetStatsReaderFail"))
require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/statistics/mockGetStatsReaderFail"))

require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/statistics/handle/mockGetStatsReaderPanic", "panic"))
require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/statistics/mockGetStatsReaderPanic", "panic"))
err = h.LoadNeededHistograms()
require.Error(t, err)
require.Regexp(t, ".*getStatsReader panic.*", err.Error())
require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/statistics/handle/mockGetStatsReaderPanic"))
require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/statistics/mockGetStatsReaderPanic"))
err = h.LoadNeededHistograms()
require.NoError(t, err)
}
Expand Down
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