Using max chunk ts

Signed-off-by: Alan Protasio <alanprot@gmail.com>

Author: alanprot

pkg/querier/batch/batch.go

@@ -100,6 +100,8 @@ func (a *iteratorAdapter) Seek(t int64) bool {
 			}
 			return true
 		} else if t <= a.underlying.MaxTime() {
+			// In this case, some timestamp inside the current underlying chunk can fulfill the seek.
+			// In this case we will call next until we find the sample as it will be faster than calling seek directly.
 			for a.underlying.Next(promchunk.BatchSize) {
 				a.curr = a.underlying.Batch()
 				if t <= a.curr.Timestamps[a.curr.Length-1] {

pkg/querier/batch/batch_test.go

@@ -64,30 +64,13 @@ func BenchmarkNewChunkMergeIterator_Seek(b *testing.B) {
 		scrapeInterval     time.Duration
 		enc                promchunk.Encoding
 	}{
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 1, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second / 2, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 1, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 1, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 2, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 1, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 10, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 1, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 100, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 1, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 1000, enc: promchunk.PrometheusXorChunk},
 		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second / 2, enc: promchunk.PrometheusXorChunk},
 		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second, enc: promchunk.PrometheusXorChunk},
 		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 2, enc: promchunk.PrometheusXorChunk},
 		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 10, enc: promchunk.PrometheusXorChunk},
+		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 50, enc: promchunk.PrometheusXorChunk},
 		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 100, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 1000, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 10 * time.Second, seekStep: 10 * time.Second / 2, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 10 * time.Second, seekStep: 10 * time.Second, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 10 * time.Second, seekStep: 10 * time.Second * 2, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 10 * time.Second, seekStep: 10 * time.Second * 10, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 10 * time.Second, seekStep: 10 * time.Second * 100, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 10 * time.Second, seekStep: 10 * time.Second * 1000, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 60 * time.Second, seekStep: 60 * time.Second / 2, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 60 * time.Second, seekStep: 60 * time.Second, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 60 * time.Second, seekStep: 60 * time.Second * 2, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 60 * time.Second, seekStep: 60 * time.Second * 10, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 60 * time.Second, seekStep: 60 * time.Second * 100, enc: promchunk.PrometheusXorChunk},
-		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 60 * time.Second, seekStep: 60 * time.Second * 1000, enc: promchunk.PrometheusXorChunk},
+		{numChunks: 1000, numSamplesPerChunk: 120, duplicationFactor: 3, scrapeInterval: 30 * time.Second, seekStep: 30 * time.Second * 200, enc: promchunk.PrometheusXorChunk},
 	}
 
 	for _, scenario := range scenarios {

pkg/querier/batch/merge.go

@@ -22,6 +22,10 @@ type mergeIterator struct {
 }
 
 func (c *mergeIterator) MaxTime() int64 {
+	if len(c.h) < 1 {
+		return -1
+	}
+
 	return c.h[0].MaxTime()
 }