Populate chunkDesc.chunkLastTime during checkpoint loading, too

storage/local/persistence.go

@@ -823,6 +823,7 @@ func (p *persistence) loadSeriesMapAndHeads() (sm *seriesMap, chunksToPersist in
 			}
 		}
 
+		headChunkClosed := true // Initial assumption.
 		for i := int64(0); i < numChunkDescs; i++ {
 			if i < persistWatermark {
 				firstTime, err := binary.ReadVarint(r)
@@ -844,6 +845,9 @@ func (p *persistence) loadSeriesMapAndHeads() (sm *seriesMap, chunksToPersist in
 				chunkDescsTotal++
 			} else {
 				// Non-persisted chunk.
+				// If there are non-persisted chunks at all, we consider
+				// the head chunk not to be closed yet.
+				headChunkClosed = false
 				encoding, err := r.ReadByte()
 				if err != nil {
 					log.Warn("Could not decode chunk type:", err)
@@ -856,15 +860,15 @@ func (p *persistence) loadSeriesMapAndHeads() (sm *seriesMap, chunksToPersist in
 					p.dirty = true
 					return sm, chunksToPersist, nil
 				}
-				chunkDescs[i] = newChunkDesc(chunk, chunk.firstTime())
+				cd := newChunkDesc(chunk, chunk.firstTime())
+				if i < numChunkDescs-1 {
+					// This is NOT the head chunk. So it's a chunk
+					// to be persisted, and we need to populate lastTime.
 					chunksToPersist++
+					cd.maybePopulateLastTime()
 				}
+				chunkDescs[i] = cd
 			}
-
-		headChunkClosed := persistWatermark >= numChunkDescs
-		if !headChunkClosed {
-			// Head chunk is not ready for persisting yet.
-			chunksToPersist--
 		}
 
 		fingerprintToSeries[model.Fingerprint(fp)] = &memorySeries{

storage/local/persistence_test.go

@@ -485,6 +485,12 @@ func testCheckpointAndLoadSeriesMapAndHeads(t *testing.T, encoding chunkEncoding
 		if loadedS1.headChunkClosed {
 			t.Error("headChunkClosed is true")
 		}
+		if loadedS1.head().chunkFirstTime != 1 {
+			t.Errorf("want chunkFirstTime in head chunk to be 1, got %d", loadedS1.head().chunkFirstTime)
+		}
+		if loadedS1.head().chunkLastTime != model.Earliest {
+			t.Error("want chunkLastTime in head chunk to be unset")
+		}
 	} else {
 		t.Errorf("couldn't find %v in loaded map", m1)
 	}
@@ -501,6 +507,12 @@ func testCheckpointAndLoadSeriesMapAndHeads(t *testing.T, encoding chunkEncoding
 		if !loadedS3.headChunkClosed {
 			t.Error("headChunkClosed is false")
 		}
+		if loadedS3.head().chunkFirstTime != 2 {
+			t.Errorf("want chunkFirstTime in head chunk to be 2, got %d", loadedS3.head().chunkFirstTime)
+		}
+		if loadedS3.head().chunkLastTime != 2 {
+			t.Errorf("want chunkLastTime in head chunk to be 2, got %d", loadedS3.head().chunkLastTime)
+		}
 	} else {
 		t.Errorf("couldn't find %v in loaded map", m3)
 	}
@@ -526,6 +538,27 @@ func testCheckpointAndLoadSeriesMapAndHeads(t *testing.T, encoding chunkEncoding
 		if loadedS4.headChunkClosed {
 			t.Error("headChunkClosed is true")
 		}
+		for i, cd := range loadedS4.chunkDescs {
+			if cd.chunkFirstTime != cd.c.firstTime() {
+				t.Errorf(
+					"chunkDesc[%d]: chunkFirstTime not consistent with chunk, want %d, got %d",
+					i, cd.c.firstTime(), cd.chunkFirstTime,
+				)
+			}
+			if i == len(loadedS4.chunkDescs)-1 {
+				// Head chunk.
+				if cd.chunkLastTime != model.Earliest {
+					t.Error("want chunkLastTime in head chunk to be unset")
+				}
+				continue
+			}
+			if cd.chunkLastTime != cd.c.newIterator().lastTimestamp() {
+				t.Errorf(
+					"chunkDesc[%d]: chunkLastTime not consistent with chunk, want %d, got %d",
+					i, cd.c.newIterator().lastTimestamp(), cd.chunkLastTime,
+				)
+			}
+		}
 	} else {
 		t.Errorf("couldn't find %v in loaded map", m4)
 	}
@@ -551,6 +584,34 @@ func testCheckpointAndLoadSeriesMapAndHeads(t *testing.T, encoding chunkEncoding
 		if loadedS5.headChunkClosed {
 			t.Error("headChunkClosed is true")
 		}
+		for i, cd := range loadedS5.chunkDescs {
+			if i < 3 {
+				// Evicted chunks.
+				if cd.chunkFirstTime == model.Earliest {
+					t.Errorf("chunkDesc[%d]: chunkLastTime not set", i)
+				}
+				continue
+			}
+			if cd.chunkFirstTime != cd.c.firstTime() {
+				t.Errorf(
+					"chunkDesc[%d]: chunkFirstTime not consistent with chunk, want %d, got %d",
+					i, cd.c.firstTime(), cd.chunkFirstTime,
+				)
+			}
+			if i == len(loadedS5.chunkDescs)-1 {
+				// Head chunk.
+				if cd.chunkLastTime != model.Earliest {
+					t.Error("want chunkLastTime in head chunk to be unset")
+				}
+				continue
+			}
+			if cd.chunkLastTime != cd.c.newIterator().lastTimestamp() {
+				t.Errorf(
+					"chunkDesc[%d]: chunkLastTime not consistent with chunk, want %d, got %d",
+					i, cd.c.newIterator().lastTimestamp(), cd.chunkLastTime,
+				)
+			}
+		}
 	} else {
 		t.Errorf("couldn't find %v in loaded map", m5)
 	}