Function TestOneCheckpointPerCompactCall

tsdb/db_test.go:3494–3606

(t *testing.T)

}

func TestOneCheckpointPerCompactCall(t *testing.T) {
	t.Parallel()
	blockRange := int64(1000)
	opts := &Options{
		RetentionDuration: blockRange * 1000,
		NoLockfile:        true,
		MinBlockDuration:  blockRange,
		MaxBlockDuration:  blockRange,
	}

	ctx := context.Background()

	db := newTestDB(t, withOpts(opts))
	db.DisableCompactions()

	// Case 1: Lot's of uncompacted data in Head.

	lbls := labels.FromStrings("foo_d", "choco_bar")
	// Append samples spanning 59 block ranges.
	app := db.Appender(context.Background())
	for i := range int64(60) {
		_, err := app.Append(0, lbls, blockRange*i, rand.Float64())
		require.NoError(t, err)
		_, err = app.Append(0, lbls, (blockRange*i)+blockRange/2, rand.Float64())
		require.NoError(t, err)
		// Rotate the WAL file so that there is >3 files for checkpoint to happen.
		_, err = db.head.wal.NextSegment()
		require.NoError(t, err)
	}
	require.NoError(t, app.Commit())

	// Check the existing WAL files.
	first, last, err := wlog.Segments(db.head.wal.Dir())
	require.NoError(t, err)
	require.Equal(t, 0, first)
	require.Equal(t, 60, last)

	require.Equal(t, 0.0, prom_testutil.ToFloat64(db.head.metrics.checkpointCreationTotal))
	require.NoError(t, db.Compact(ctx))
	require.Equal(t, 1.0, prom_testutil.ToFloat64(db.head.metrics.checkpointCreationTotal))

	// As the data spans for 59 blocks, 58 go to disk and 1 remains in Head.
	require.Len(t, db.Blocks(), 58)
	// Though WAL was truncated only once, head should be truncated after each compaction.
	require.Equal(t, 58.0, prom_testutil.ToFloat64(db.head.metrics.headTruncateTotal))

	// The compaction should have only truncated first 2/3 of WAL (while also rotating the files).
	first, last, err = wlog.Segments(db.head.wal.Dir())
	require.NoError(t, err)
	require.Equal(t, 40, first)
	require.Equal(t, 61, last)

	// The first checkpoint would be for first 2/3rd of WAL, hence till 39.
	// That should be the last checkpoint.
	_, cno, err := wlog.LastCheckpoint(db.head.wal.Dir())
	require.NoError(t, err)
	require.Equal(t, 39, cno)