VictoriaMetrics/lib/streamaggr/count_series.go
Aliaksandr Valialkin 36be090cd5
lib/streamaggr: follow-up for 7cb894a777
- Use bytesutil.InternString() instead of strings.Clone() for inputKey and outputKey in aggregatorpushSamples().
  This should reduce string allocation rate, since strings can be re-used between aggrState flushes.
- Reduce memory allocations at dedupAggrShard by storing dedupAggrSample by value in the active series map.
- Remove duplicate call to bytesutil.InternBytes() at Deduplicator, since it is already called inside dedupAggr.pushSamples().
- Add missing string interning at rateAggrState.pushSamples().

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6402
2024-06-07 16:27:26 +02:00

92 lines
2.3 KiB
Go

package streamaggr
import (
"sync"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
"github.com/cespare/xxhash/v2"
)
// countSeriesAggrState calculates output=count_series, e.g. the number of unique series.
type countSeriesAggrState struct {
m sync.Map
}
type countSeriesStateValue struct {
mu sync.Mutex
m map[uint64]struct{}
deleted bool
}
func newCountSeriesAggrState() *countSeriesAggrState {
return &countSeriesAggrState{}
}
func (as *countSeriesAggrState) pushSamples(samples []pushSample) {
for i := range samples {
s := &samples[i]
inputKey, outputKey := getInputOutputKey(s.key)
// Count unique hashes over the inputKeys instead of unique inputKey values.
// This reduces memory usage at the cost of possible hash collisions for distinct inputKey values.
h := xxhash.Sum64(bytesutil.ToUnsafeBytes(inputKey))
again:
v, ok := as.m.Load(outputKey)
if !ok {
// The entry is missing in the map. Try creating it.
v = &countSeriesStateValue{
m: map[uint64]struct{}{
h: {},
},
}
outputKey = bytesutil.InternString(outputKey)
vNew, loaded := as.m.LoadOrStore(outputKey, v)
if !loaded {
// The entry has been added to the map.
continue
}
// Update the entry created by a concurrent goroutine.
v = vNew
}
sv := v.(*countSeriesStateValue)
sv.mu.Lock()
deleted := sv.deleted
if !deleted {
if _, ok := sv.m[h]; !ok {
sv.m[h] = struct{}{}
}
}
sv.mu.Unlock()
if deleted {
// The entry has been deleted by the concurrent call to flushState
// Try obtaining and updating the entry again.
goto again
}
}
}
func (as *countSeriesAggrState) flushState(ctx *flushCtx, resetState bool) {
currentTimeMsec := int64(fasttime.UnixTimestamp()) * 1000
m := &as.m
m.Range(func(k, v interface{}) bool {
if resetState {
// Atomically delete the entry from the map, so new entry is created for the next flush.
m.Delete(k)
}
sv := v.(*countSeriesStateValue)
sv.mu.Lock()
n := len(sv.m)
if resetState {
// Mark the entry as deleted, so it won't be updated anymore by concurrent pushSample() calls.
sv.deleted = true
}
sv.mu.Unlock()
key := k.(string)
ctx.appendSeries(key, "count_series", currentTimeMsec, float64(n))
return true
})
}