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[PERF] TSDB: Cache all symbols for compaction 

Trade a bit more memory for a lot less CPU spent looking up symbols.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
This commit is contained in:
Bryan Boreham 2024-11-24 15:59:44 +00:00
parent 634afbc130
commit e98c19c1ce
1 changed files with 17 additions and 35 deletions
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52
tsdb/index/index.go
View File

@ -110,12 +110,6 @@ func newCRC32() hash.Hash32 {
return crc32.New(castagnoliTable)
}
type symbolCacheEntry struct {
index uint32
lastValueIndex uint32
lastValue string
}
type PostingsEncoder func(*encoding.Encbuf, []uint32) error
type PostingsDecoder func(encoding.Decbuf) (int, Postings, error)
@ -146,7 +140,7 @@ type Writer struct {
symbols *Symbols
symbolFile *fileutil.MmapFile
lastSymbol string
symbolCache map[string]symbolCacheEntry
symbolCache map[string]uint32 // From symbol to index in table.
labelIndexes []labelIndexHashEntry // Label index offsets.
labelNames map[string]uint64 // Label names, and their usage.
@ -246,7 +240,7 @@ func NewWriterWithEncoder(ctx context.Context, fn string, encoder PostingsEncode
buf1: encoding.Encbuf{B: make([]byte, 0, 1<<22)},
buf2: encoding.Encbuf{B: make([]byte, 0, 1<<22)},
symbolCache: make(map[string]symbolCacheEntry, 1<<8),
symbolCache: make(map[string]uint32, 1<<16),
labelNames: make(map[string]uint64, 1<<8),
crc32: newCRC32(),
postingsEncoder: encoder,
@ -478,29 +472,16 @@ func (w *Writer) AddSeries(ref storage.SeriesRef, lset labels.Labels, chunks ...
w.buf2.PutUvarint(lset.Len())
if err := lset.Validate(func(l labels.Label) error {
var err error
cacheEntry, ok := w.symbolCache[l.Name]
nameIndex := cacheEntry.index
nameIndex, ok := w.symbolCache[l.Name]
if !ok {
nameIndex, err = w.symbols.ReverseLookup(l.Name)
if err != nil {
return fmt.Errorf("symbol entry for %q does not exist, %w", l.Name, err)
}
return fmt.Errorf("symbol entry for %q does not exist", l.Name)
}
w.labelNames[l.Name]++
w.buf2.PutUvarint32(nameIndex)
valueIndex := cacheEntry.lastValueIndex
if !ok || cacheEntry.lastValue != l.Value {
valueIndex, err = w.symbols.ReverseLookup(l.Value)
if err != nil {
return fmt.Errorf("symbol entry for %q does not exist, %w", l.Value, err)
}
w.symbolCache[l.Name] = symbolCacheEntry{
index: nameIndex,
lastValueIndex: valueIndex,
lastValue: l.Value,
}
valueIndex, ok := w.symbolCache[l.Value]
if !ok {
return fmt.Errorf("symbol entry for %q does not exist", l.Value)
}
w.buf2.PutUvarint32(valueIndex)
return nil
@ -559,6 +540,7 @@ func (w *Writer) AddSymbol(sym string) error {
return fmt.Errorf("symbol %q out-of-order", sym)
}
w.lastSymbol = sym
w.symbolCache[sym] = uint32(w.numSymbols)
w.numSymbols++
w.buf1.Reset()
w.buf1.PutUvarintStr(sym)
@ -644,9 +626,9 @@ func (w *Writer) writeLabelIndices() error {
values = values[:0]
}
current = name
sid, err := w.symbols.ReverseLookup(value)
if err != nil {
return err
sid, ok := w.symbolCache[value]
if !ok {
return fmt.Errorf("symbol entry for %q does not exist", string(value))
}
values = append(values, sid)
}
@ -918,9 +900,9 @@ func (w *Writer) writePostingsToTmpFiles() error {
nameSymbols := map[uint32]string{}
for _, name := range batchNames {
sid, err := w.symbols.ReverseLookup(name)
if err != nil {
return err
sid, ok := w.symbolCache[name]
if !ok {
return fmt.Errorf("symbol entry for %q does not exist", name)
}
nameSymbols[sid] = name
}
@ -957,9 +939,9 @@ func (w *Writer) writePostingsToTmpFiles() error {
for _, name := range batchNames {
// Write out postings for this label name.
sid, err := w.symbols.ReverseLookup(name)
if err != nil {
return err
sid, ok := w.symbolCache[name]
if !ok {
return fmt.Errorf("symbol entry for %q does not exist", name)
}
values := make([]uint32, 0, len(postings[sid]))
for v := range postings[sid] {