TSDB: do not allocate exemplars buffer if exemplars are disabled
@@ -1086,7 +1086,7 @@ func (a *initAppender) Append(ref uint64, lset labels.Labels, t int64, v float64
func (a *initAppender) AppendExemplar(ref uint64, l labels.Labels, e exemplar.Exemplar) (uint64, error) {
// Check if exemplar storage is enabled.
- if a.head.opts.NumExemplars == 0 {
+ if a.head.opts.NumExemplars <= 0 {
return 0, nil
}
@@ -1142,6 +1142,12 @@ func (h *Head) appender() *headAppender {
appendID := h.iso.newAppendID()
cleanupAppendIDsBelow := h.iso.lowWatermark()
+ // Allocate the exemplars buffer only if exemplars are enabled.
+ var exemplarsBuf []exemplarWithSeriesRef
+ if h.opts.NumExemplars > 0 {
+ exemplarsBuf = h.getExemplarBuffer()
+ }
+
return &headAppender{
head: h,
minValidTime: h.appendableMinValidTime(),
@@ -1149,7 +1155,7 @@ func (h *Head) appender() *headAppender {
maxt: math.MinInt64,
samples: h.getAppendBuffer(),
sampleSeries: h.getSeriesBuffer(),
- exemplars: h.getExemplarBuffer(),
+ exemplars: exemplarsBuf,
appendID: appendID,
cleanupAppendIDsBelow: cleanupAppendIDsBelow,
exemplarAppender: h.exemplars,
@@ -1204,6 +1210,10 @@ func (h *Head) getExemplarBuffer() []exemplarWithSeriesRef {
}
func (h *Head) putExemplarBuffer(b []exemplarWithSeriesRef) {
+ if b == nil {
+ return
+ }
+
//nolint:staticcheck // Ignore SA6002 safe to ignore and actually fixing it has some performance penalty.
h.exemplarsPool.Put(b[:0])
}
@@ -1317,7 +1327,7 @@ func (a *headAppender) Append(ref uint64, lset labels.Labels, t int64, v float64
// use getOrCreate or make any of the lset sanity checks that Append does.
func (a *headAppender) AppendExemplar(ref uint64, _ labels.Labels, e exemplar.Exemplar) (uint64, error) {
// Check if exemplar storage is enabled.
- if a.head.opts.NumExemplars == 0 {
+ if a.head.opts.NumExemplars <= 0 {
return 0, nil
}
