Add unit test and also protect truncateOOO

Signed-off-by: Jesus Vazquez <jesus.vazquez@grafana.com>

tsdb/db_test.go

@@ -4333,6 +4333,106 @@ func TestOOOCompactionWithNormalCompaction(t *testing.T) {
 	verifySamples(db.Blocks()[1], 250, 350)
 }
 
+// TestOOOCompactionWithDisabledWriteLog tests the scenario where the TSDB is
+// configured to not have wal and wbl but its able to compact both the in-order
+// and out-of-order head
+func TestOOOCompactionWithDisabledWriteLog(t *testing.T) {
+	dir := t.TempDir()
+
+	opts := DefaultOptions()
+	opts.OutOfOrderCapMax = 30
+	opts.OutOfOrderTimeWindow = 300 * time.Minute.Milliseconds()
+	opts.WALSegmentSize = -1 // disabled WAL and WBL
+
+	db, err := Open(dir, nil, nil, opts, nil)
+	require.NoError(t, err)
+	db.DisableCompactions() // We want to manually call it.
+	t.Cleanup(func() {
+		require.NoError(t, db.Close())
+	})
+
+	series1 := labels.FromStrings("foo", "bar1")
+	series2 := labels.FromStrings("foo", "bar2")
+
+	addSamples := func(fromMins, toMins int64) {
+		app := db.Appender(context.Background())
+		for min := fromMins; min <= toMins; min++ {
+			ts := min * time.Minute.Milliseconds()
+			_, err := app.Append(0, series1, ts, float64(ts))
+			require.NoError(t, err)
+			_, err = app.Append(0, series2, ts, float64(2*ts))
+			require.NoError(t, err)
+		}
+		require.NoError(t, app.Commit())
+	}
+
+	// Add an in-order samples.
+	addSamples(250, 350)
+
+	// Add ooo samples that will result into a single block.
+	addSamples(90, 110)
+
+	// Checking that ooo chunk is not empty.
+	for _, lbls := range []labels.Labels{series1, series2} {
+		ms, created, err := db.head.getOrCreate(lbls.Hash(), lbls)
+		require.NoError(t, err)
+		require.False(t, created)
+		require.Greater(t, ms.ooo.oooHeadChunk.chunk.NumSamples(), 0)
+	}
+
+	// If the normal Head is not compacted, the OOO head compaction does not take place.
+	require.NoError(t, db.Compact())
+	require.Equal(t, len(db.Blocks()), 0)
+
+	// Add more in-order samples in future that would trigger the compaction.
+	addSamples(400, 450)
+
+	// No blocks before compaction.
+	require.Equal(t, len(db.Blocks()), 0)
+
+	// Compacts normal and OOO head.
+	require.NoError(t, db.Compact())
+
+	// 2 blocks exist now. [0, 120), [250, 360)
+	require.Equal(t, len(db.Blocks()), 2)
+	require.Equal(t, int64(0), db.Blocks()[0].MinTime())
+	require.Equal(t, 120*time.Minute.Milliseconds(), db.Blocks()[0].MaxTime())
+	require.Equal(t, 250*time.Minute.Milliseconds(), db.Blocks()[1].MinTime())
+	require.Equal(t, 360*time.Minute.Milliseconds(), db.Blocks()[1].MaxTime())
+
+	// Checking that ooo chunk is empty.
+	for _, lbls := range []labels.Labels{series1, series2} {
+		ms, created, err := db.head.getOrCreate(lbls.Hash(), lbls)
+		require.NoError(t, err)
+		require.False(t, created)
+		require.Nil(t, ms.ooo)
+	}
+
+	verifySamples := func(block *Block, fromMins, toMins int64) {
+		series1Samples := make([]tsdbutil.Sample, 0, toMins-fromMins+1)
+		series2Samples := make([]tsdbutil.Sample, 0, toMins-fromMins+1)
+		for min := fromMins; min <= toMins; min++ {
+			ts := min * time.Minute.Milliseconds()
+			series1Samples = append(series1Samples, sample{ts, float64(ts), nil, nil})
+			series2Samples = append(series2Samples, sample{ts, float64(2 * ts), nil, nil})
+		}
+		expRes := map[string][]tsdbutil.Sample{
+			series1.String(): series1Samples,
+			series2.String(): series2Samples,
+		}
+
+		q, err := NewBlockQuerier(block, math.MinInt64, math.MaxInt64)
+		require.NoError(t, err)
+
+		actRes := query(t, q, labels.MustNewMatcher(labels.MatchRegexp, "foo", "bar.*"))
+		require.Equal(t, expRes, actRes)
+	}
+
+	// Checking for expected data in the blocks.
+	verifySamples(db.Blocks()[0], 90, 110)
+	verifySamples(db.Blocks()[1], 250, 350)
+}
+
 func Test_Querier_OOOQuery(t *testing.T) {
 	opts := DefaultOptions()
 	opts.OutOfOrderCapMax = 30

tsdb/head.go

@@ -1207,6 +1207,10 @@ func (h *Head) truncateOOO(lastWBLFile int, minOOOMmapRef chunks.ChunkDiskMapper
 		}
 	}
 
+	if h.wbl == nil {
+		return nil
+	}
+
 	return h.wbl.Truncate(lastWBLFile)
 }
 

tsdb/ooo_head_read.go

@@ -277,11 +277,11 @@ type OOOCompactionHead struct {
 // on the sample append latency. So call NewOOOCompactionHead only right before compaction.
 func NewOOOCompactionHead(head *Head) (*OOOCompactionHead, error) {
 	ch := &OOOCompactionHead{
-		chunkRange:  head.chunkRange.Load(),
-		mint:        math.MaxInt64,
-		maxt:        math.MinInt64,
-		lastWBLFile: 0,
+		chunkRange: head.chunkRange.Load(),
+		mint:       math.MaxInt64,
+		maxt:       math.MinInt64,
 	}
+
 	if head.wbl != nil {
 		lastWBLFile, err := head.wbl.NextSegmentSync()
 		if err != nil {