diff --git a/promql/engine.go b/promql/engine.go
index 4f37ced261..29e3869ada 100644
--- a/promql/engine.go
+++ b/promql/engine.go
@@ -517,7 +517,12 @@ func (ng *Engine) populateIterators(ctx context.Context, s *EvalStmt) (storage.Q
 	Inspect(s.Expr, func(node Node) bool {
 		switch n := node.(type) {
 		case *VectorSelector:
-			n.series, err = expandSeriesSet(querier.Select(n.LabelMatchers...))
+			set, err := querier.Select(n.LabelMatchers...)
+			if err != nil {
+				level.Error(ng.logger).Log("msg", "error selecting series set", "err", err)
+				return false
+			}
+			n.series, err = expandSeriesSet(set)
 			if err != nil {
 				// TODO(fabxc): use multi-error.
 				level.Error(ng.logger).Log("msg", "error expanding series set", "err", err)
@@ -529,7 +534,12 @@ func (ng *Engine) populateIterators(ctx context.Context, s *EvalStmt) (storage.Q
 			}
 
 		case *MatrixSelector:
-			n.series, err = expandSeriesSet(querier.Select(n.LabelMatchers...))
+			set, err := querier.Select(n.LabelMatchers...)
+			if err != nil {
+				level.Error(ng.logger).Log("msg", "error selecting series set", "err", err)
+				return false
+			}
+			n.series, err = expandSeriesSet(set)
 			if err != nil {
 				level.Error(ng.logger).Log("msg", "error expanding series set", "err", err)
 				return false
diff --git a/rules/manager_test.go b/rules/manager_test.go
index 4f68a9f1b6..5ff947129a 100644
--- a/rules/manager_test.go
+++ b/rules/manager_test.go
@@ -172,9 +172,16 @@ func TestStaleness(t *testing.T) {
 	querier, err := storage.Querier(context.Background(), 0, 2000)
 	testutil.Ok(t, err)
 	defer querier.Close()
-	matcher, _ := labels.NewMatcher(labels.MatchEqual, model.MetricNameLabel, "a_plus_one")
-	samples, err := readSeriesSet(querier.Select(matcher))
+
+	matcher, err := labels.NewMatcher(labels.MatchEqual, model.MetricNameLabel, "a_plus_one")
 	testutil.Ok(t, err)
+
+	set, err := querier.Select(matcher)
+	testutil.Ok(t, err)
+
+	samples, err := readSeriesSet(set)
+	testutil.Ok(t, err)
+
 	metric := labels.FromStrings(model.MetricNameLabel, "a_plus_one").String()
 	metricSample, ok := samples[metric]
 
diff --git a/storage/fanout.go b/storage/fanout.go
index 62f9730448..061d993af7 100644
--- a/storage/fanout.go
+++ b/storage/fanout.go
@@ -216,12 +216,16 @@ func NewMergeQuerier(queriers []Querier) Querier {
 }
 
 // Select returns a set of series that matches the given label matchers.
-func (q *mergeQuerier) Select(matchers ...*labels.Matcher) SeriesSet {
+func (q *mergeQuerier) Select(matchers ...*labels.Matcher) (SeriesSet, error) {
 	seriesSets := make([]SeriesSet, 0, len(q.queriers))
 	for _, querier := range q.queriers {
-		seriesSets = append(seriesSets, querier.Select(matchers...))
+		set, err := querier.Select(matchers...)
+		if err != nil {
+			return nil, err
+		}
+		seriesSets = append(seriesSets, set)
 	}
-	return newMergeSeriesSet(seriesSets)
+	return newMergeSeriesSet(seriesSets), nil
 }
 
 // LabelValues returns all potential values for a label name.
diff --git a/storage/interface.go b/storage/interface.go
index f9bfc6a27f..71261b2c94 100644
--- a/storage/interface.go
+++ b/storage/interface.go
@@ -52,7 +52,7 @@ type Queryable interface {
 // Querier provides reading access to time series data.
 type Querier interface {
 	// Select returns a set of series that matches the given label matchers.
-	Select(...*labels.Matcher) SeriesSet
+	Select(...*labels.Matcher) (SeriesSet, error)
 
 	// LabelValues returns all potential values for a label name.
 	LabelValues(name string) ([]string, error)
diff --git a/storage/noop.go b/storage/noop.go
index 358cf2611c..a5ff1bc9b4 100644
--- a/storage/noop.go
+++ b/storage/noop.go
@@ -22,8 +22,8 @@ func NoopQuerier() Querier {
 	return noopQuerier{}
 }
 
-func (noopQuerier) Select(...*labels.Matcher) SeriesSet {
-	return NoopSeriesSet()
+func (noopQuerier) Select(...*labels.Matcher) (SeriesSet, error) {
+	return NoopSeriesSet(), nil
 }
 
 func (noopQuerier) LabelValues(name string) ([]string, error) {
diff --git a/storage/remote/read.go b/storage/remote/read.go
index be87c3f6fe..e49d3524a5 100644
--- a/storage/remote/read.go
+++ b/storage/remote/read.go
@@ -43,18 +43,18 @@ type querier struct {
 
 // Select implements storage.Querier and uses the given matchers to read series
 // sets from the Client.
-func (q *querier) Select(matchers ...*labels.Matcher) storage.SeriesSet {
+func (q *querier) Select(matchers ...*labels.Matcher) (storage.SeriesSet, error) {
 	query, err := ToQuery(q.mint, q.maxt, matchers)
 	if err != nil {
-		return errSeriesSet{err: err}
+		return nil, err
 	}
 
 	res, err := q.client.Read(q.ctx, query)
 	if err != nil {
-		return errSeriesSet{err: err}
+		return nil, err
 	}
 
-	return FromQueryResult(res)
+	return FromQueryResult(res), nil
 }
 
 // LabelValues implements storage.Querier and is a noop.
@@ -91,10 +91,13 @@ type externalLabelsQuerier struct {
 // Select adds equality matchers for all external labels to the list of matchers
 // before calling the wrapped storage.Queryable. The added external labels are
 // removed from the returned series sets.
-func (q externalLabelsQuerier) Select(matchers ...*labels.Matcher) storage.SeriesSet {
+func (q externalLabelsQuerier) Select(matchers ...*labels.Matcher) (storage.SeriesSet, error) {
 	m, added := q.addExternalLabels(matchers)
-	s := q.Querier.Select(m...)
-	return newSeriesSetFilter(s, added)
+	s, err := q.Querier.Select(m...)
+	if err != nil {
+		return nil, err
+	}
+	return newSeriesSetFilter(s, added), nil
 }
 
 // PreferLocalStorageFilter returns a QueryableFunc which creates a NoopQuerier
@@ -141,7 +144,7 @@ type requiredMatchersQuerier struct {
 
 // Select returns a NoopSeriesSet if the given matchers don't match the label
 // set of the requiredMatchersQuerier. Otherwise it'll call the wrapped querier.
-func (q requiredMatchersQuerier) Select(matchers ...*labels.Matcher) storage.SeriesSet {
+func (q requiredMatchersQuerier) Select(matchers ...*labels.Matcher) (storage.SeriesSet, error) {
 	ms := q.requiredMatchers
 	for _, m := range matchers {
 		for i, r := range ms {
@@ -155,7 +158,7 @@ func (q requiredMatchersQuerier) Select(matchers ...*labels.Matcher) storage.Ser
 		}
 	}
 	if len(ms) > 0 {
-		return storage.NoopSeriesSet()
+		return storage.NoopSeriesSet(), nil
 	}
 	return q.Querier.Select(matchers...)
 }
diff --git a/storage/remote/read_test.go b/storage/remote/read_test.go
index 0bcdc45c76..f61ab37423 100644
--- a/storage/remote/read_test.go
+++ b/storage/remote/read_test.go
@@ -41,9 +41,12 @@ func TestExternalLabelsQuerierSelect(t *testing.T) {
 		Querier:        mockQuerier{},
 		externalLabels: model.LabelSet{"region": "europe"},
 	}
-
 	want := newSeriesSetFilter(mockSeriesSet{}, q.externalLabels)
-	if have := q.Select(matchers...); !reflect.DeepEqual(want, have) {
+	have, err := q.Select(matchers...)
+	if err != nil {
+		t.Error(err)
+	}
+	if !reflect.DeepEqual(want, have) {
 		t.Errorf("expected series set %+v, got %+v", want, have)
 	}
 }
@@ -154,8 +157,8 @@ type mockSeriesSet struct {
 	storage.SeriesSet
 }
 
-func (mockQuerier) Select(...*labels.Matcher) storage.SeriesSet {
-	return mockSeriesSet{}
+func (mockQuerier) Select(...*labels.Matcher) (storage.SeriesSet, error) {
+	return mockSeriesSet{}, nil
 }
 
 func TestPreferLocalStorageFilter(t *testing.T) {
@@ -310,7 +313,11 @@ func TestRequiredLabelsQuerierSelect(t *testing.T) {
 			requiredMatchers: test.requiredMatchers,
 		}
 
-		if want, have := test.seriesSet, q.Select(test.matchers...); want != have {
+		have, err := q.Select(test.matchers...)
+		if err != nil {
+			t.Error(err)
+		}
+		if want := test.seriesSet; want != have {
 			t.Errorf("%d. expected series set %+v, got %+v", i, want, have)
 		}
 		if want, have := test.requiredMatchers, q.requiredMatchers; !reflect.DeepEqual(want, have) {
diff --git a/storage/tsdb/tsdb.go b/storage/tsdb/tsdb.go
index f077765444..070488fbf1 100644
--- a/storage/tsdb/tsdb.go
+++ b/storage/tsdb/tsdb.go
@@ -188,14 +188,17 @@ type querier struct {
 	q tsdb.Querier
 }
 
-func (q querier) Select(oms ...*labels.Matcher) storage.SeriesSet {
+func (q querier) Select(oms ...*labels.Matcher) (storage.SeriesSet, error) {
 	ms := make([]tsdbLabels.Matcher, 0, len(oms))
 
 	for _, om := range oms {
 		ms = append(ms, convertMatcher(om))
 	}
-
-	return seriesSet{set: q.q.Select(ms...)}
+	set, err := q.q.Select(ms...)
+	if err != nil {
+		return nil, err
+	}
+	return seriesSet{set: set}, nil
 }
 
 func (q querier) LabelValues(name string) ([]string, error) { return q.q.LabelValues(name) }
diff --git a/vendor/github.com/prometheus/tsdb/block.go b/vendor/github.com/prometheus/tsdb/block.go
index 63b468f272..8456cb3762 100644
--- a/vendor/github.com/prometheus/tsdb/block.go
+++ b/vendor/github.com/prometheus/tsdb/block.go
@@ -133,7 +133,7 @@ func writeMetaFile(dir string, meta *BlockMeta) error {
 	return renameFile(tmp, path)
 }
 
-// Block represents a directory of time series data covering a continous time range.
+// Block represents a directory of time series data covering a continuous time range.
 type Block struct {
 	mtx            sync.RWMutex
 	closing        bool
@@ -142,10 +142,9 @@ type Block struct {
 	dir  string
 	meta BlockMeta
 
-	chunkr *chunkReader
-	indexr *indexReader
-
-	tombstones tombstoneReader
+	chunkr     ChunkReader
+	indexr     IndexReader
+	tombstones TombstoneReader
 }
 
 // OpenBlock opens the block in the directory. It can be passed a chunk pool, which is used
@@ -156,11 +155,11 @@ func OpenBlock(dir string, pool chunks.Pool) (*Block, error) {
 		return nil, err
 	}
 
-	cr, err := newChunkReader(chunkDir(dir), pool)
+	cr, err := NewDirChunkReader(chunkDir(dir), pool)
 	if err != nil {
 		return nil, err
 	}
-	ir, err := newIndexReader(dir)
+	ir, err := NewFileIndexReader(filepath.Join(dir, "index"))
 	if err != nil {
 		return nil, err
 	}
@@ -284,13 +283,15 @@ func (pb *Block) Delete(mint, maxt int64, ms ...labels.Matcher) error {
 		return ErrClosing
 	}
 
-	pr := newPostingsReader(pb.indexr)
-	p, absent := pr.Select(ms...)
+	p, absent, err := PostingsForMatchers(pb.indexr, ms...)
+	if err != nil {
+		return errors.Wrap(err, "select series")
+	}
 
 	ir := pb.indexr
 
 	// Choose only valid postings which have chunks in the time-range.
-	stones := map[uint64]Intervals{}
+	stones := memTombstones{}
 
 	var lset labels.Labels
 	var chks []ChunkMeta
@@ -322,16 +323,21 @@ Outer:
 		return p.Err()
 	}
 
-	// Merge the current and new tombstones.
-	for k, v := range stones {
-		pb.tombstones.add(k, v[0])
+	err = pb.tombstones.Iter(func(id uint64, ivs Intervals) error {
+		for _, iv := range ivs {
+			stones.add(id, iv)
+			pb.meta.Stats.NumTombstones++
+		}
+		return nil
+	})
+	if err != nil {
+		return err
 	}
+	pb.tombstones = stones
 
 	if err := writeTombstoneFile(pb.dir, pb.tombstones); err != nil {
 		return err
 	}
-
-	pb.meta.Stats.NumTombstones = uint64(len(pb.tombstones))
 	return writeMetaFile(pb.dir, &pb.meta)
 }
 
diff --git a/vendor/github.com/prometheus/tsdb/block.prof b/vendor/github.com/prometheus/tsdb/block.prof
new file mode 100644
index 0000000000..122ef97f33
--- /dev/null
+++ b/vendor/github.com/prometheus/tsdb/block.prof
@@ -0,0 +1,12 @@
+--- contention:
+cycles/second=2494255279
+80179315716 1 @ 0x10061bb 0x10e008c 0x10e3934 0x10dfd30 0x10e1468 0x10e0431 0x1328cdb 0x102e9fd 0x105cea1
+80176248000 1 @ 0x1065c12 0x1313b9d 0x10dfd30 0x105cea1
+37792267436 303368 @ 0x10061fb 0x131dc08 0x105cea1
+21607828 1098 @ 0x10648fe 0x10650d7 0x1064fca 0x12e5a74 0x12e5df2 0x131d969 0x105cea1
+1272473 118 @ 0x10648fe 0x1065232 0x10651c6 0x1064cb0 0x12e5bcc 0x131dc50 0x105cea1
+851800 1 @ 0x10061bb 0x1313bc6 0x10dfd30 0x105cea1
+818628 59 @ 0x10648fe 0x1065232 0x10651c6 0x1064ebf 0x12e5a74 0x12e5df2 0x131d969 0x105cea1
+501203 2 @ 0x1005473 0x12e5ed4 0x131d969 0x105cea1
+7738 1 @ 0x10648fe 0x1064d19 0x12e5bcc 0x131dc50 0x105cea1
+3846 1 @ 0x1005473 0x10e373b 0x10dfd3a 0x10e1468 0x10e0431 0x1328cdb 0x102e9fd 0x105cea1
diff --git a/vendor/github.com/prometheus/tsdb/chunks.go b/vendor/github.com/prometheus/tsdb/chunks.go
index f6e329b790..30ab93f805 100644
--- a/vendor/github.com/prometheus/tsdb/chunks.go
+++ b/vendor/github.com/prometheus/tsdb/chunks.go
@@ -298,7 +298,7 @@ type ChunkReader interface {
 // of series data.
 type chunkReader struct {
 	// The underlying bytes holding the encoded series data.
-	bs [][]byte
+	bs []ByteSlice
 
 	// Closers for resources behind the byte slices.
 	cs []io.Closer
@@ -306,8 +306,32 @@ type chunkReader struct {
 	pool chunks.Pool
 }
 
-// newChunkReader returns a new chunkReader based on mmaped files found in dir.
-func newChunkReader(dir string, pool chunks.Pool) (*chunkReader, error) {
+func newChunkReader(bs []ByteSlice, cs []io.Closer, pool chunks.Pool) (*chunkReader, error) {
+	cr := chunkReader{pool: pool, bs: bs, cs: cs}
+
+	for i, b := range cr.bs {
+		if b.Len() < 4 {
+			return nil, errors.Wrapf(errInvalidSize, "validate magic in segment %d", i)
+		}
+		// Verify magic number.
+		if m := binary.BigEndian.Uint32(b.Range(0, 4)); m != MagicChunks {
+			return nil, fmt.Errorf("invalid magic number %x", m)
+		}
+	}
+	return &cr, nil
+}
+
+// NewChunkReader returns a new chunk reader against the given byte slices.
+func NewChunkReader(bs []ByteSlice, pool chunks.Pool) (ChunkReader, error) {
+	if pool == nil {
+		pool = chunks.NewPool()
+	}
+	return newChunkReader(bs, nil, pool)
+}
+
+// NewDirChunkReader returns a new ChunkReader against sequentially numbered files in the
+// given directory.
+func NewDirChunkReader(dir string, pool chunks.Pool) (ChunkReader, error) {
 	files, err := sequenceFiles(dir)
 	if err != nil {
 		return nil, err
@@ -315,27 +339,19 @@ func newChunkReader(dir string, pool chunks.Pool) (*chunkReader, error) {
 	if pool == nil {
 		pool = chunks.NewPool()
 	}
-	cr := chunkReader{pool: pool}
+
+	var bs []ByteSlice
+	var cs []io.Closer
 
 	for _, fn := range files {
 		f, err := openMmapFile(fn)
 		if err != nil {
 			return nil, errors.Wrapf(err, "mmap files")
 		}
-		cr.cs = append(cr.cs, f)
-		cr.bs = append(cr.bs, f.b)
+		cs = append(cs, f)
+		bs = append(bs, realByteSlice(f.b))
 	}
-
-	for i, b := range cr.bs {
-		if len(b) < 4 {
-			return nil, errors.Wrapf(errInvalidSize, "validate magic in segment %d", i)
-		}
-		// Verify magic number.
-		if m := binary.BigEndian.Uint32(b[:4]); m != MagicChunks {
-			return nil, fmt.Errorf("invalid magic number %x", m)
-		}
-	}
-	return &cr, nil
+	return newChunkReader(bs, cs, pool)
 }
 
 func (s *chunkReader) Close() error {
@@ -352,16 +368,18 @@ func (s *chunkReader) Chunk(ref uint64) (chunks.Chunk, error) {
 	}
 	b := s.bs[seq]
 
-	if int(off) >= len(b) {
-		return nil, errors.Errorf("offset %d beyond data size %d", off, len(b))
+	if int(off) >= b.Len() {
+		return nil, errors.Errorf("offset %d beyond data size %d", off, b.Len())
 	}
-	b = b[off:]
+	// With the minimum chunk length this should never cause us reading
+	// over the end of the slice.
+	r := b.Range(off, off+binary.MaxVarintLen32)
 
-	l, n := binary.Uvarint(b)
+	l, n := binary.Uvarint(r)
 	if n < 0 {
 		return nil, fmt.Errorf("reading chunk length failed")
 	}
-	b = b[n:]
+	r = b.Range(off+n, off+n+int(l))
 
-	return s.pool.Get(chunks.Encoding(b[0]), b[1:1+l])
+	return s.pool.Get(chunks.Encoding(r[0]), r[1:1+l])
 }
diff --git a/vendor/github.com/prometheus/tsdb/chunks/xor.go b/vendor/github.com/prometheus/tsdb/chunks/xor.go
index 501db704ad..dcee466f7f 100644
--- a/vendor/github.com/prometheus/tsdb/chunks/xor.go
+++ b/vendor/github.com/prometheus/tsdb/chunks/xor.go
@@ -46,8 +46,7 @@ package chunks
 import (
 	"encoding/binary"
 	"math"
-
-	bits "github.com/dgryski/go-bits"
+	"math/bits"
 )
 
 // XORChunk holds XOR encoded sample data.
@@ -197,8 +196,8 @@ func (a *xorAppender) writeVDelta(v float64) {
 	}
 	a.b.writeBit(one)
 
-	leading := uint8(bits.Clz(vDelta))
-	trailing := uint8(bits.Ctz(vDelta))
+	leading := uint8(bits.LeadingZeros64(vDelta))
+	trailing := uint8(bits.TrailingZeros64(vDelta))
 
 	// Clamp number of leading zeros to avoid overflow when encoding.
 	if leading >= 32 {
diff --git a/vendor/github.com/prometheus/tsdb/compact.go b/vendor/github.com/prometheus/tsdb/compact.go
index 955ba3cafb..35cb36a63c 100644
--- a/vendor/github.com/prometheus/tsdb/compact.go
+++ b/vendor/github.com/prometheus/tsdb/compact.go
@@ -52,7 +52,7 @@ type Compactor interface {
 	Plan(dir string) ([]string, error)
 
 	// Write persists a Block into a directory.
-	Write(dest string, b BlockReader, mint, maxt int64) error
+	Write(dest string, b BlockReader, mint, maxt int64) (ulid.ULID, error)
 
 	// Compact runs compaction against the provided directories. Must
 	// only be called concurrently with results of Plan().
@@ -321,7 +321,7 @@ func (c *LeveledCompactor) Compact(dest string, dirs ...string) (err error) {
 	return c.write(dest, compactBlockMetas(uid, metas...), blocks...)
 }
 
-func (c *LeveledCompactor) Write(dest string, b BlockReader, mint, maxt int64) error {
+func (c *LeveledCompactor) Write(dest string, b BlockReader, mint, maxt int64) (ulid.ULID, error) {
 	entropy := rand.New(rand.NewSource(time.Now().UnixNano()))
 	uid := ulid.MustNew(ulid.Now(), entropy)
 
@@ -333,7 +333,7 @@ func (c *LeveledCompactor) Write(dest string, b BlockReader, mint, maxt int64) e
 	meta.Compaction.Level = 1
 	meta.Compaction.Sources = []ulid.ULID{uid}
 
-	return c.write(dest, meta, b)
+	return uid, c.write(dest, meta, b)
 }
 
 // instrumentedChunkWriter is used for level 1 compactions to record statistics
@@ -418,7 +418,7 @@ func (c *LeveledCompactor) write(dest string, meta *BlockMeta, blocks ...BlockRe
 	}
 
 	// Create an empty tombstones file.
-	if err := writeTombstoneFile(tmp, newEmptyTombstoneReader()); err != nil {
+	if err := writeTombstoneFile(tmp, EmptyTombstoneReader()); err != nil {
 		return errors.Wrap(err, "write new tombstones file")
 	}
 
@@ -453,7 +453,7 @@ func (c *LeveledCompactor) write(dest string, meta *BlockMeta, blocks ...BlockRe
 // of the provided blocks. It returns meta information for the new block.
 func (c *LeveledCompactor) populateBlock(blocks []BlockReader, meta *BlockMeta, indexw IndexWriter, chunkw ChunkWriter) error {
 	var (
-		set        compactionSet
+		set        ChunkSeriesSet
 		allSymbols = make(map[string]struct{}, 1<<16)
 		closers    = []io.Closer{}
 	)
@@ -597,18 +597,11 @@ func (c *LeveledCompactor) populateBlock(blocks []BlockReader, meta *BlockMeta,
 	return nil
 }
 
-type compactionSet interface {
-	Next() bool
-	At() (labels.Labels, []ChunkMeta, Intervals)
-	Err() error
-}
-
 type compactionSeriesSet struct {
 	p          Postings
 	index      IndexReader
 	chunks     ChunkReader
 	tombstones TombstoneReader
-	series     SeriesSet
 
 	l         labels.Labels
 	c         []ChunkMeta
@@ -631,7 +624,11 @@ func (c *compactionSeriesSet) Next() bool {
 	}
 	var err error
 
-	c.intervals = c.tombstones.Get(c.p.At())
+	c.intervals, err = c.tombstones.Get(c.p.At())
+	if err != nil {
+		c.err = errors.Wrap(err, "get tombstones")
+		return false
+	}
 
 	if err = c.index.Series(c.p.At(), &c.l, &c.c); err != nil {
 		c.err = errors.Wrapf(err, "get series %d", c.p.At())
@@ -675,7 +672,7 @@ func (c *compactionSeriesSet) At() (labels.Labels, []ChunkMeta, Intervals) {
 }
 
 type compactionMerger struct {
-	a, b compactionSet
+	a, b ChunkSeriesSet
 
 	aok, bok  bool
 	l         labels.Labels
@@ -688,7 +685,7 @@ type compactionSeries struct {
 	chunks []*ChunkMeta
 }
 
-func newCompactionMerger(a, b compactionSet) (*compactionMerger, error) {
+func newCompactionMerger(a, b ChunkSeriesSet) (*compactionMerger, error) {
 	c := &compactionMerger{
 		a: a,
 		b: b,
diff --git a/vendor/github.com/prometheus/tsdb/cpu.pro b/vendor/github.com/prometheus/tsdb/cpu.pro
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/vendor/github.com/prometheus/tsdb/cpu.prof b/vendor/github.com/prometheus/tsdb/cpu.prof
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/vendor/github.com/prometheus/tsdb/db.go b/vendor/github.com/prometheus/tsdb/db.go
index 3622a77f5e..a748a6e1f5 100644
--- a/vendor/github.com/prometheus/tsdb/db.go
+++ b/vendor/github.com/prometheus/tsdb/db.go
@@ -52,7 +52,7 @@ var DefaultOptions = &Options{
 
 // Options of the DB storage.
 type Options struct {
-	// The interval at which the write ahead log is flushed to disc.
+	// The interval at which the write ahead log is flushed to disk.
 	WALFlushInterval time.Duration
 
 	// Duration of persisted data to keep.
@@ -101,7 +101,6 @@ type DB struct {
 	opts      *Options
 	chunkPool chunks.Pool
 	compactor Compactor
-	wal       WAL
 
 	// Mutex for that must be held when modifying the general block layout.
 	mtx    sync.RWMutex
@@ -142,7 +141,7 @@ func newDBMetrics(db *DB, r prometheus.Registerer) *dbMetrics {
 	})
 	m.reloadsFailed = prometheus.NewCounter(prometheus.CounterOpts{
 		Name: "prometheus_tsdb_reloads_failures_total",
-		Help: "Number of times the database failed to reload black data from disk.",
+		Help: "Number of times the database failed to reload block data from disk.",
 	})
 	m.compactionsTriggered = prometheus.NewCounter(prometheus.CounterOpts{
 		Name: "prometheus_tsdb_compactions_triggered_total",
@@ -278,16 +277,23 @@ func (db *DB) retentionCutoff() (bool, error) {
 	}
 
 	db.mtx.RLock()
-	defer db.mtx.RUnlock()
+	blocks := db.blocks[:]
+	db.mtx.RUnlock()
 
-	if len(db.blocks) == 0 {
+	if len(blocks) == 0 {
 		return false, nil
 	}
 
-	last := db.blocks[len(db.blocks)-1]
-	mint := last.Meta().MaxTime - int64(db.opts.RetentionDuration)
+	last := blocks[len(db.blocks)-1]
 
-	return retentionCutoff(db.dir, mint)
+	mint := last.Meta().MaxTime - int64(db.opts.RetentionDuration)
+	dirs, err := retentionCutoffDirs(db.dir, mint)
+	if err != nil {
+		return false, err
+	}
+
+	// This will close the dirs and then delete the dirs.
+	return len(dirs) > 0, db.reload(dirs...)
 }
 
 // Appender opens a new appender against the database.
@@ -345,7 +351,7 @@ func (db *DB) compact() (changes bool, err error) {
 			mint: mint,
 			maxt: maxt,
 		}
-		if err = db.compactor.Write(db.dir, head, mint, maxt); err != nil {
+		if _, err = db.compactor.Write(db.dir, head, mint, maxt); err != nil {
 			return changes, errors.Wrap(err, "persist head block")
 		}
 		changes = true
@@ -389,40 +395,37 @@ func (db *DB) compact() (changes bool, err error) {
 	return changes, nil
 }
 
-// retentionCutoff deletes all directories of blocks in dir that are strictly
+// retentionCutoffDirs returns all directories of blocks in dir that are strictly
 // before mint.
-func retentionCutoff(dir string, mint int64) (bool, error) {
+func retentionCutoffDirs(dir string, mint int64) ([]string, error) {
 	df, err := fileutil.OpenDir(dir)
 	if err != nil {
-		return false, errors.Wrapf(err, "open directory")
+		return nil, errors.Wrapf(err, "open directory")
 	}
 	defer df.Close()
 
 	dirs, err := blockDirs(dir)
 	if err != nil {
-		return false, errors.Wrapf(err, "list block dirs %s", dir)
+		return nil, errors.Wrapf(err, "list block dirs %s", dir)
 	}
 
-	changes := false
+	delDirs := []string{}
 
 	for _, dir := range dirs {
 		meta, err := readMetaFile(dir)
 		if err != nil {
-			return changes, errors.Wrapf(err, "read block meta %s", dir)
+			return nil, errors.Wrapf(err, "read block meta %s", dir)
 		}
 		// The first block we encounter marks that we crossed the boundary
 		// of deletable blocks.
 		if meta.MaxTime >= mint {
 			break
 		}
-		changes = true
 
-		if err := os.RemoveAll(dir); err != nil {
-			return changes, err
-		}
+		delDirs = append(delDirs, dir)
 	}
 
-	return changes, fileutil.Fsync(df)
+	return delDirs, nil
 }
 
 func (db *DB) getBlock(id ulid.ULID) (*Block, bool) {
@@ -572,6 +575,7 @@ func (db *DB) Close() error {
 	if db.lockf != nil {
 		merr.Add(db.lockf.Unlock())
 	}
+	merr.Add(db.head.Close())
 	return merr.Err()
 }
 
@@ -615,7 +619,8 @@ func (db *DB) Snapshot(dir string) error {
 			return errors.Wrap(err, "error snapshotting headblock")
 		}
 	}
-	return db.compactor.Write(dir, db.head, db.head.MinTime(), db.head.MaxTime())
+	_, err := db.compactor.Write(dir, db.head, db.head.MinTime(), db.head.MaxTime())
+	return errors.Wrap(err, "snapshot head block")
 }
 
 // Querier returns a new querier over the data partition for the given time range.
diff --git a/vendor/github.com/prometheus/tsdb/db_unix.go b/vendor/github.com/prometheus/tsdb/db_unix.go
index 09bb74f3ca..02c411d7f2 100644
--- a/vendor/github.com/prometheus/tsdb/db_unix.go
+++ b/vendor/github.com/prometheus/tsdb/db_unix.go
@@ -11,19 +11,20 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build !windows,!plan9,!solaris
+// +build !windows,!plan9
 
 package tsdb
 
 import (
 	"os"
-	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 func mmap(f *os.File, length int) ([]byte, error) {
-	return syscall.Mmap(int(f.Fd()), 0, length, syscall.PROT_READ, syscall.MAP_SHARED)
+	return unix.Mmap(int(f.Fd()), 0, length, unix.PROT_READ, unix.MAP_SHARED)
 }
 
 func munmap(b []byte) (err error) {
-	return syscall.Munmap(b)
+	return unix.Munmap(b)
 }
diff --git a/vendor/github.com/prometheus/tsdb/encoding_helpers.go b/vendor/github.com/prometheus/tsdb/encoding_helpers.go
index 9aa4ba4097..b55c7fda96 100644
--- a/vendor/github.com/prometheus/tsdb/encoding_helpers.go
+++ b/vendor/github.com/prometheus/tsdb/encoding_helpers.go
@@ -3,6 +3,7 @@ package tsdb
 import (
 	"encoding/binary"
 	"hash"
+	"hash/crc32"
 	"unsafe"
 )
 
@@ -77,6 +78,11 @@ func (d *decbuf) uvarint32() uint32 { return uint32(d.uvarint64()) }
 func (d *decbuf) be32int() int      { return int(d.be32()) }
 func (d *decbuf) be64int64() int64  { return int64(d.be64()) }
 
+// crc32 returns a CRC32 checksum over the remaining bytes.
+func (d *decbuf) crc32() uint32 {
+	return crc32.Checksum(d.b, castagnoliTable)
+}
+
 func (d *decbuf) uvarintStr() string {
 	l := d.uvarint64()
 	if d.e != nil {
diff --git a/vendor/github.com/prometheus/tsdb/head.go b/vendor/github.com/prometheus/tsdb/head.go
index 3d2bdb9c6f..d149cb1d9c 100644
--- a/vendor/github.com/prometheus/tsdb/head.go
+++ b/vendor/github.com/prometheus/tsdb/head.go
@@ -66,7 +66,7 @@ type Head struct {
 
 	postings *memPostings // postings lists for terms
 
-	tombstones tombstoneReader
+	tombstones memTombstones
 }
 
 type headMetrics struct {
@@ -186,7 +186,7 @@ func NewHead(r prometheus.Registerer, l log.Logger, wal WAL, chunkRange int64) (
 		values:     map[string]stringset{},
 		symbols:    map[string]struct{}{},
 		postings:   newUnorderedMemPostings(),
-		tombstones: newEmptyTombstoneReader(),
+		tombstones: memTombstones{},
 	}
 	h.metrics = newHeadMetrics(h, r)
 
@@ -574,8 +574,10 @@ func (h *Head) Delete(mint, maxt int64, ms ...labels.Matcher) error {
 
 	ir := h.indexRange(mint, maxt)
 
-	pr := newPostingsReader(ir)
-	p, absent := pr.Select(ms...)
+	p, absent, err := PostingsForMatchers(ir, ms...)
+	if err != nil {
+		return errors.Wrap(err, "select series")
+	}
 
 	var stones []Stone
 
@@ -739,6 +741,11 @@ func (h *Head) MaxTime() int64 {
 	return atomic.LoadInt64(&h.maxTime)
 }
 
+// Close flushes the WAL and closes the head.
+func (h *Head) Close() error {
+	return h.wal.Close()
+}
+
 type headChunkReader struct {
 	head       *Head
 	mint, maxt int64
diff --git a/vendor/github.com/prometheus/tsdb/index.go b/vendor/github.com/prometheus/tsdb/index.go
index 258db74d25..6895c16f42 100644
--- a/vendor/github.com/prometheus/tsdb/index.go
+++ b/vendor/github.com/prometheus/tsdb/index.go
@@ -560,7 +560,7 @@ type StringTuples interface {
 
 type indexReader struct {
 	// The underlying byte slice holding the encoded series data.
-	b   []byte
+	b   ByteSlice
 	toc indexTOC
 
 	// Close that releases the underlying resources of the byte slice.
@@ -575,33 +575,62 @@ type indexReader struct {
 	// prevents memory faults when applications work with read symbols after
 	// the block has been unmapped.
 	symbols map[uint32]string
+
+	crc32 hash.Hash32
 }
 
 var (
-	errInvalidSize = fmt.Errorf("invalid size")
-	errInvalidFlag = fmt.Errorf("invalid flag")
+	errInvalidSize     = fmt.Errorf("invalid size")
+	errInvalidFlag     = fmt.Errorf("invalid flag")
+	errInvalidChecksum = fmt.Errorf("invalid checksum")
 )
 
-// NewIndexReader returns a new IndexReader on the given directory.
-func NewIndexReader(dir string) (IndexReader, error) { return newIndexReader(dir) }
+// ByteSlice abstracts a byte slice.
+type ByteSlice interface {
+	Len() int
+	Range(start, end int) []byte
+}
 
-// newIndexReader returns a new indexReader on the given directory.
-func newIndexReader(dir string) (*indexReader, error) {
-	f, err := openMmapFile(filepath.Join(dir, "index"))
+type realByteSlice []byte
+
+func (b realByteSlice) Len() int {
+	return len(b)
+}
+
+func (b realByteSlice) Range(start, end int) []byte {
+	return b[start:end]
+}
+
+func (b realByteSlice) Sub(start, end int) ByteSlice {
+	return b[start:end]
+}
+
+// NewIndexReader returns a new IndexReader on the given byte slice.
+func NewIndexReader(b ByteSlice) (IndexReader, error) {
+	return newIndexReader(b, nil)
+}
+
+// NewFileIndexReader returns a new index reader against the given index file.
+func NewFileIndexReader(path string) (IndexReader, error) {
+	f, err := openMmapFile(path)
 	if err != nil {
 		return nil, err
 	}
-	r := &indexReader{
-		b:       f.b,
-		c:       f,
-		symbols: map[uint32]string{},
-	}
+	return newIndexReader(realByteSlice(f.b), f)
+}
 
+func newIndexReader(b ByteSlice, c io.Closer) (*indexReader, error) {
+	r := &indexReader{
+		b:       b,
+		c:       c,
+		symbols: map[uint32]string{},
+		crc32:   newCRC32(),
+	}
 	// Verify magic number.
-	if len(f.b) < 4 {
+	if b.Len() < 4 {
 		return nil, errors.Wrap(errInvalidSize, "index header")
 	}
-	if m := binary.BigEndian.Uint32(r.b[:4]); m != MagicIndex {
+	if m := binary.BigEndian.Uint32(r.b.Range(0, 4)); m != MagicIndex {
 		return nil, errors.Errorf("invalid magic number %x", m)
 	}
 
@@ -611,6 +640,7 @@ func newIndexReader(dir string) (*indexReader, error) {
 	if err := r.readSymbols(int(r.toc.symbols)); err != nil {
 		return nil, errors.Wrap(err, "read symbols")
 	}
+	var err error
 
 	r.labels, err = r.readOffsetTable(r.toc.labelIndicesTable)
 	if err != nil {
@@ -621,7 +651,17 @@ func newIndexReader(dir string) (*indexReader, error) {
 }
 
 func (r *indexReader) readTOC() error {
-	d := r.decbufAt(len(r.b) - indexTOCLen)
+	if r.b.Len() < indexTOCLen {
+		return errInvalidSize
+	}
+	b := r.b.Range(r.b.Len()-indexTOCLen, r.b.Len())
+
+	expCRC := binary.BigEndian.Uint32(b[len(b)-4:])
+	d := decbuf{b: b[:len(b)-4]}
+
+	if d.crc32() != expCRC {
+		return errInvalidChecksum
+	}
 
 	r.toc.symbols = d.be64()
 	r.toc.series = d.be64()
@@ -630,16 +670,61 @@ func (r *indexReader) readTOC() error {
 	r.toc.postings = d.be64()
 	r.toc.postingsTable = d.be64()
 
-	// TODO(fabxc): validate checksum.
-
-	return nil
+	return d.err()
 }
 
+// decbufAt returns a new decoding buffer. It expects the first 4 bytes
+// after offset to hold the big endian encoded content length, followed by the contents and the expected
+// checksum.
 func (r *indexReader) decbufAt(off int) decbuf {
-	if len(r.b) < off {
+	if r.b.Len() < off+4 {
 		return decbuf{e: errInvalidSize}
 	}
-	return decbuf{b: r.b[off:]}
+	b := r.b.Range(off, off+4)
+	l := int(binary.BigEndian.Uint32(b))
+
+	if r.b.Len() < off+4+l+4 {
+		return decbuf{e: errInvalidSize}
+	}
+
+	// Load bytes holding the contents plus a CRC32 checksum.
+	b = r.b.Range(off+4, off+4+l+4)
+	dec := decbuf{b: b[:len(b)-4]}
+
+	if exp := binary.BigEndian.Uint32(b[len(b)-4:]); dec.crc32() != exp {
+		return decbuf{e: errInvalidChecksum}
+	}
+	return dec
+}
+
+// decbufUvarintAt returns a new decoding buffer. It expects the first bytes
+// after offset to hold the uvarint-encoded buffers length, followed by the contents and the expected
+// checksum.
+func (r *indexReader) decbufUvarintAt(off int) decbuf {
+	// We never have to access this method at the far end of the byte slice. Thus just checking
+	// against the MaxVarintLen32 is sufficient.
+	if r.b.Len() < off+binary.MaxVarintLen32 {
+		return decbuf{e: errInvalidSize}
+	}
+	b := r.b.Range(off, off+binary.MaxVarintLen32)
+
+	l, n := binary.Uvarint(b)
+	if n > binary.MaxVarintLen32 {
+		return decbuf{e: errors.New("invalid uvarint")}
+	}
+
+	if r.b.Len() < off+n+int(l)+4 {
+		return decbuf{e: errInvalidSize}
+	}
+
+	// Load bytes holding the contents plus a CRC32 checksum.
+	b = r.b.Range(off+n, off+n+int(l)+4)
+	dec := decbuf{b: b[:len(b)-4]}
+
+	if dec.crc32() != binary.BigEndian.Uint32(b[len(b)-4:]) {
+		return decbuf{e: errInvalidChecksum}
+	}
+	return dec
 }
 
 // readSymbols reads the symbol table fully into memory and allocates proper strings for them.
@@ -649,22 +734,22 @@ func (r *indexReader) readSymbols(off int) error {
 	if off == 0 {
 		return nil
 	}
+	d := r.decbufAt(off)
+
 	var (
-		d1      = r.decbufAt(int(off))
-		d2      = d1.decbuf(d1.be32int())
-		origLen = d2.len()
-		cnt     = d2.be32int()
+		origLen = d.len()
+		cnt     = d.be32int()
 		basePos = uint32(off) + 4
-		nextPos = basePos + uint32(origLen-d2.len())
+		nextPos = basePos + uint32(origLen-d.len())
 	)
-	for d2.err() == nil && d2.len() > 0 && cnt > 0 {
-		s := d2.uvarintStr()
+	for d.err() == nil && d.len() > 0 && cnt > 0 {
+		s := d.uvarintStr()
 		r.symbols[uint32(nextPos)] = s
 
-		nextPos = basePos + uint32(origLen-d2.len())
+		nextPos = basePos + uint32(origLen-d.len())
 		cnt--
 	}
-	return d2.err()
+	return d.err()
 }
 
 // readOffsetTable reads an offset table at the given position and returns a map
@@ -672,53 +757,29 @@ func (r *indexReader) readSymbols(off int) error {
 func (r *indexReader) readOffsetTable(off uint64) (map[string]uint32, error) {
 	const sep = "\xff"
 
-	var (
-		d1  = r.decbufAt(int(off))
-		d2  = d1.decbuf(d1.be32int())
-		cnt = d2.be32()
-	)
+	d := r.decbufAt(int(off))
+	cnt := d.be32()
 
-	res := make(map[string]uint32, 512)
+	res := make(map[string]uint32, cnt)
 
-	for d2.err() == nil && d2.len() > 0 && cnt > 0 {
-		keyCount := int(d2.uvarint())
+	for d.err() == nil && d.len() > 0 && cnt > 0 {
+		keyCount := int(d.uvarint())
 		keys := make([]string, 0, keyCount)
 
 		for i := 0; i < keyCount; i++ {
-			keys = append(keys, d2.uvarintStr())
+			keys = append(keys, d.uvarintStr())
 		}
-		res[strings.Join(keys, sep)] = uint32(d2.uvarint())
+		res[strings.Join(keys, sep)] = uint32(d.uvarint())
 
 		cnt--
 	}
-
-	// TODO(fabxc): verify checksum from remainer of d1.
-	return res, d2.err()
+	return res, d.err()
 }
 
 func (r *indexReader) Close() error {
 	return r.c.Close()
 }
 
-func (r *indexReader) section(o uint32) (byte, []byte, error) {
-	b := r.b[o:]
-
-	if len(b) < 5 {
-		return 0, nil, errors.Wrap(errInvalidSize, "read header")
-	}
-
-	flag := b[0]
-	l := binary.BigEndian.Uint32(b[1:5])
-
-	b = b[5:]
-
-	// b must have the given length plus 4 bytes for the CRC32 checksum.
-	if len(b) < int(l)+4 {
-		return 0, nil, errors.Wrap(errInvalidSize, "section content")
-	}
-	return flag, b[:l], nil
-}
-
 func (r *indexReader) lookupSymbol(o uint32) (string, error) {
 	s, ok := r.symbols[o]
 	if !ok {
@@ -748,21 +809,17 @@ func (r *indexReader) LabelValues(names ...string) (StringTuples, error) {
 		//return nil, fmt.Errorf("label index doesn't exist")
 	}
 
-	d1 := r.decbufAt(int(off))
-	d2 := d1.decbuf(d1.be32int())
+	d := r.decbufAt(int(off))
 
-	nc := d2.be32int()
-	d2.be32() // consume unused value entry count.
+	nc := d.be32int()
+	d.be32() // consume unused value entry count.
 
-	if d2.err() != nil {
-		return nil, errors.Wrap(d2.err(), "read label value index")
+	if d.err() != nil {
+		return nil, errors.Wrap(d.err(), "read label value index")
 	}
-
-	// TODO(fabxc): verify checksum in 4 remaining bytes of d1.
-
 	st := &serializedStringTuples{
 		l:      nc,
-		b:      d2.get(),
+		b:      d.get(),
 		lookup: r.lookupSymbol,
 	}
 	return st, nil
@@ -785,20 +842,19 @@ func (r *indexReader) LabelIndices() ([][]string, error) {
 }
 
 func (r *indexReader) Series(ref uint64, lbls *labels.Labels, chks *[]ChunkMeta) error {
-	d1 := r.decbufAt(int(ref))
-	d2 := d1.decbuf(int(d1.uvarint()))
+	d := r.decbufUvarintAt(int(ref))
 
 	*lbls = (*lbls)[:0]
 	*chks = (*chks)[:0]
 
-	k := int(d2.uvarint())
+	k := int(d.uvarint())
 
 	for i := 0; i < k; i++ {
-		lno := uint32(d2.uvarint())
-		lvo := uint32(d2.uvarint())
+		lno := uint32(d.uvarint())
+		lvo := uint32(d.uvarint())
 
-		if d2.err() != nil {
-			return errors.Wrap(d2.err(), "read series label offsets")
+		if d.err() != nil {
+			return errors.Wrap(d.err(), "read series label offsets")
 		}
 
 		ln, err := r.lookupSymbol(lno)
@@ -814,15 +870,15 @@ func (r *indexReader) Series(ref uint64, lbls *labels.Labels, chks *[]ChunkMeta)
 	}
 
 	// Read the chunks meta data.
-	k = int(d2.uvarint())
+	k = int(d.uvarint())
 
 	if k == 0 {
 		return nil
 	}
 
-	t0 := d2.varint64()
-	maxt := int64(d2.uvarint64()) + t0
-	ref0 := int64(d2.uvarint64())
+	t0 := d.varint64()
+	maxt := int64(d.uvarint64()) + t0
+	ref0 := int64(d.uvarint64())
 
 	*chks = append(*chks, ChunkMeta{
 		Ref:     uint64(ref0),
@@ -832,14 +888,14 @@ func (r *indexReader) Series(ref uint64, lbls *labels.Labels, chks *[]ChunkMeta)
 	t0 = maxt
 
 	for i := 1; i < k; i++ {
-		mint := int64(d2.uvarint64()) + t0
-		maxt := int64(d2.uvarint64()) + mint
+		mint := int64(d.uvarint64()) + t0
+		maxt := int64(d.uvarint64()) + mint
 
-		ref0 += d2.varint64()
+		ref0 += d.varint64()
 		t0 = maxt
 
-		if d2.err() != nil {
-			return errors.Wrapf(d2.err(), "read meta for chunk %d", i)
+		if d.err() != nil {
+			return errors.Wrapf(d.err(), "read meta for chunk %d", i)
 		}
 
 		*chks = append(*chks, ChunkMeta{
@@ -848,10 +904,7 @@ func (r *indexReader) Series(ref uint64, lbls *labels.Labels, chks *[]ChunkMeta)
 			MaxTime: maxt,
 		})
 	}
-
-	// TODO(fabxc): verify CRC32.
-
-	return nil
+	return d.err()
 }
 
 func (r *indexReader) Postings(name, value string) (Postings, error) {
@@ -862,19 +915,10 @@ func (r *indexReader) Postings(name, value string) (Postings, error) {
 	if !ok {
 		return emptyPostings, nil
 	}
+	d := r.decbufAt(int(off))
+	d.be32() // consume unused postings list length.
 
-	d1 := r.decbufAt(int(off))
-	d2 := d1.decbuf(d1.be32int())
-
-	d2.be32() // consume unused postings list length.
-
-	if d2.err() != nil {
-		return nil, errors.Wrap(d2.err(), "get postings bytes")
-	}
-
-	// TODO(fabxc): read checksum from 4 remainer bytes of d1 and verify.
-
-	return newBigEndianPostings(d2.get()), nil
+	return newBigEndianPostings(d.get()), errors.Wrap(d.err(), "get postings bytes")
 }
 
 func (r *indexReader) SortedPostings(p Postings) Postings {
diff --git a/vendor/github.com/prometheus/tsdb/postings.go b/vendor/github.com/prometheus/tsdb/postings.go
index 2647f4dd8e..63fb1e31a0 100644
--- a/vendor/github.com/prometheus/tsdb/postings.go
+++ b/vendor/github.com/prometheus/tsdb/postings.go
@@ -165,6 +165,11 @@ func (e errPostings) Err() error       { return e.err }
 
 var emptyPostings = errPostings{}
 
+// EmptyPostings returns a postings list that's always empty.
+func EmptyPostings() Postings {
+	return emptyPostings
+}
+
 // Intersect returns a new postings list over the intersection of the
 // input postings.
 func Intersect(its ...Postings) Postings {
diff --git a/vendor/github.com/prometheus/tsdb/querier.go b/vendor/github.com/prometheus/tsdb/querier.go
index ed8b64ceac..37672c7156 100644
--- a/vendor/github.com/prometheus/tsdb/querier.go
+++ b/vendor/github.com/prometheus/tsdb/querier.go
@@ -27,7 +27,7 @@ import (
 // time range.
 type Querier interface {
 	// Select returns a set of series that matches the given label matchers.
-	Select(...labels.Matcher) SeriesSet
+	Select(...labels.Matcher) (SeriesSet, error)
 
 	// LabelValues returns all potential values for a label name.
 	LabelValues(string) ([]string, error)
@@ -81,20 +81,29 @@ func (q *querier) LabelValuesFor(string, labels.Label) ([]string, error) {
 	return nil, fmt.Errorf("not implemented")
 }
 
-func (q *querier) Select(ms ...labels.Matcher) SeriesSet {
+func (q *querier) Select(ms ...labels.Matcher) (SeriesSet, error) {
 	return q.sel(q.blocks, ms)
 
 }
 
-func (q *querier) sel(qs []Querier, ms []labels.Matcher) SeriesSet {
+func (q *querier) sel(qs []Querier, ms []labels.Matcher) (SeriesSet, error) {
 	if len(qs) == 0 {
-		return nopSeriesSet{}
+		return EmptySeriesSet(), nil
 	}
 	if len(qs) == 1 {
 		return qs[0].Select(ms...)
 	}
 	l := len(qs) / 2
-	return newMergedSeriesSet(q.sel(qs[:l], ms), q.sel(qs[l:], ms))
+
+	a, err := q.sel(qs[:l], ms)
+	if err != nil {
+		return nil, err
+	}
+	b, err := q.sel(qs[l:], ms)
+	if err != nil {
+		return nil, err
+	}
+	return newMergedSeriesSet(a, b), nil
 }
 
 func (q *querier) Close() error {
@@ -141,20 +150,14 @@ type blockQuerier struct {
 	mint, maxt int64
 }
 
-func (q *blockQuerier) Select(ms ...labels.Matcher) SeriesSet {
-	pr := newPostingsReader(q.index)
-
-	p, absent := pr.Select(ms...)
-
+func (q *blockQuerier) Select(ms ...labels.Matcher) (SeriesSet, error) {
+	base, err := LookupChunkSeries(q.index, q.tombstones, ms...)
+	if err != nil {
+		return nil, err
+	}
 	return &blockSeriesSet{
 		set: &populatedChunkSeries{
-			set: &baseChunkSeries{
-				p:      p,
-				index:  q.index,
-				absent: absent,
-
-				tombstones: q.tombstones,
-			},
+			set:    base,
 			chunks: q.chunks,
 			mint:   q.mint,
 			maxt:   q.maxt,
@@ -162,7 +165,7 @@ func (q *blockQuerier) Select(ms ...labels.Matcher) SeriesSet {
 
 		mint: q.mint,
 		maxt: q.maxt,
-	}
+	}, nil
 }
 
 func (q *blockQuerier) LabelValues(name string) ([]string, error) {
@@ -196,16 +199,10 @@ func (q *blockQuerier) Close() error {
 	return merr.Err()
 }
 
-// postingsReader is used to select matching postings from an IndexReader.
-type postingsReader struct {
-	index IndexReader
-}
-
-func newPostingsReader(i IndexReader) *postingsReader {
-	return &postingsReader{index: i}
-}
-
-func (r *postingsReader) Select(ms ...labels.Matcher) (Postings, []string) {
+// PostingsForMatchers assembles a single postings iterator against the index reader
+// based on the given matchers. It returns a list of label names that must be manually
+// checked to not exist in series the postings list points to.
+func PostingsForMatchers(index IndexReader, ms ...labels.Matcher) (Postings, []string, error) {
 	var (
 		its    []Postings
 		absent []string
@@ -217,12 +214,13 @@ func (r *postingsReader) Select(ms ...labels.Matcher) (Postings, []string) {
 			absent = append(absent, m.Name())
 			continue
 		}
-		its = append(its, r.selectSingle(m))
+		it, err := postingsForMatcher(index, m)
+		if err != nil {
+			return nil, nil, err
+		}
+		its = append(its, it)
 	}
-
-	p := Intersect(its...)
-
-	return r.index.SortedPostings(p), absent
+	return index.SortedPostings(Intersect(its...)), absent, nil
 }
 
 // tuplesByPrefix uses binary search to find prefix matches within ts.
@@ -256,33 +254,33 @@ func tuplesByPrefix(m *labels.PrefixMatcher, ts StringTuples) ([]string, error)
 	return matches, nil
 }
 
-func (r *postingsReader) selectSingle(m labels.Matcher) Postings {
+func postingsForMatcher(index IndexReader, m labels.Matcher) (Postings, error) {
 	// Fast-path for equal matching.
 	if em, ok := m.(*labels.EqualMatcher); ok {
-		it, err := r.index.Postings(em.Name(), em.Value())
+		it, err := index.Postings(em.Name(), em.Value())
 		if err != nil {
-			return errPostings{err: err}
+			return nil, err
 		}
-		return it
+		return it, nil
 	}
 
-	tpls, err := r.index.LabelValues(m.Name())
+	tpls, err := index.LabelValues(m.Name())
 	if err != nil {
-		return errPostings{err: err}
+		return nil, err
 	}
 
 	var res []string
 	if pm, ok := m.(*labels.PrefixMatcher); ok {
 		res, err = tuplesByPrefix(pm, tpls)
 		if err != nil {
-			return errPostings{err: err}
+			return nil, err
 		}
 
 	} else {
 		for i := 0; i < tpls.Len(); i++ {
 			vals, err := tpls.At(i)
 			if err != nil {
-				return errPostings{err: err}
+				return nil, err
 			}
 			if m.Matches(vals[0]) {
 				res = append(res, vals[0])
@@ -291,20 +289,20 @@ func (r *postingsReader) selectSingle(m labels.Matcher) Postings {
 	}
 
 	if len(res) == 0 {
-		return emptyPostings
+		return EmptyPostings(), nil
 	}
 
 	var rit []Postings
 
 	for _, v := range res {
-		it, err := r.index.Postings(m.Name(), v)
+		it, err := index.Postings(m.Name(), v)
 		if err != nil {
-			return errPostings{err: err}
+			return nil, err
 		}
 		rit = append(rit, it)
 	}
 
-	return Merge(rit...)
+	return Merge(rit...), nil
 }
 
 func mergeStrings(a, b []string) []string {
@@ -342,11 +340,12 @@ type SeriesSet interface {
 	Err() error
 }
 
-type nopSeriesSet struct{}
+var emptySeriesSet = errSeriesSet{}
 
-func (nopSeriesSet) Next() bool { return false }
-func (nopSeriesSet) At() Series { return nil }
-func (nopSeriesSet) Err() error { return nil }
+// EmptySeriesSet returns a series set that's always empty.
+func EmptySeriesSet() SeriesSet {
+	return emptySeriesSet
+}
 
 // mergedSeriesSet takes two series sets as a single series set. The input series sets
 // must be sorted and sequential in time, i.e. if they have the same label set,
@@ -418,7 +417,7 @@ func (s *mergedSeriesSet) Next() bool {
 	return true
 }
 
-type chunkSeriesSet interface {
+type ChunkSeriesSet interface {
 	Next() bool
 	At() (labels.Labels, []ChunkMeta, Intervals)
 	Err() error
@@ -438,6 +437,24 @@ type baseChunkSeries struct {
 	err       error
 }
 
+// LookupChunkSeries retrieves all series for the given matchers and returns a ChunkSeriesSet
+// over them. It drops chunks based on tombstones in the given reader.
+func LookupChunkSeries(ir IndexReader, tr TombstoneReader, ms ...labels.Matcher) (ChunkSeriesSet, error) {
+	if tr == nil {
+		tr = EmptyTombstoneReader()
+	}
+	p, absent, err := PostingsForMatchers(ir, ms...)
+	if err != nil {
+		return nil, err
+	}
+	return &baseChunkSeries{
+		p:          p,
+		index:      ir,
+		tombstones: tr,
+		absent:     absent,
+	}, nil
+}
+
 func (s *baseChunkSeries) At() (labels.Labels, []ChunkMeta, Intervals) {
 	return s.lset, s.chks, s.intervals
 }
@@ -448,6 +465,7 @@ func (s *baseChunkSeries) Next() bool {
 	var (
 		lset   labels.Labels
 		chunks []ChunkMeta
+		err    error
 	)
 Outer:
 	for s.p.Next() {
@@ -470,7 +488,11 @@ Outer:
 
 		s.lset = lset
 		s.chks = chunks
-		s.intervals = s.tombstones.Get(s.p.At())
+		s.intervals, err = s.tombstones.Get(s.p.At())
+		if err != nil {
+			s.err = errors.Wrap(err, "get tombstones")
+			return false
+		}
 
 		if len(s.intervals) > 0 {
 			// Only those chunks that are not entirely deleted.
@@ -496,7 +518,7 @@ Outer:
 // with known chunk references. It filters out chunks that do not fit the
 // given time range.
 type populatedChunkSeries struct {
-	set        chunkSeriesSet
+	set        ChunkSeriesSet
 	chunks     ChunkReader
 	mint, maxt int64
 
@@ -553,7 +575,7 @@ func (s *populatedChunkSeries) Next() bool {
 
 // blockSeriesSet is a set of series from an inverted index query.
 type blockSeriesSet struct {
-	set chunkSeriesSet
+	set ChunkSeriesSet
 	err error
 	cur Series
 
diff --git a/vendor/github.com/prometheus/tsdb/tombstones.go b/vendor/github.com/prometheus/tsdb/tombstones.go
index d43cd0bd0c..8ca089e617 100644
--- a/vendor/github.com/prometheus/tsdb/tombstones.go
+++ b/vendor/github.com/prometheus/tsdb/tombstones.go
@@ -35,12 +35,17 @@ const (
 
 // TombstoneReader gives access to tombstone intervals by series reference.
 type TombstoneReader interface {
-	Get(ref uint64) Intervals
+	// Get returns deletion intervals for the series with the given reference.
+	Get(ref uint64) (Intervals, error)
 
+	// Iter calls the given function for each encountered interval.
+	Iter(func(uint64, Intervals) error) error
+
+	// Close any underlying resources
 	Close() error
 }
 
-func writeTombstoneFile(dir string, tr tombstoneReader) error {
+func writeTombstoneFile(dir string, tr TombstoneReader) error {
 	path := filepath.Join(dir, tombstoneFilename)
 	tmp := path + ".tmp"
 	hash := newCRC32()
@@ -67,19 +72,21 @@ func writeTombstoneFile(dir string, tr tombstoneReader) error {
 
 	mw := io.MultiWriter(f, hash)
 
-	for k, v := range tr {
-		for _, itv := range v {
+	tr.Iter(func(ref uint64, ivs Intervals) error {
+		for _, iv := range ivs {
 			buf.reset()
-			buf.putUvarint64(k)
-			buf.putVarint64(itv.Mint)
-			buf.putVarint64(itv.Maxt)
+
+			buf.putUvarint64(ref)
+			buf.putVarint64(iv.Mint)
+			buf.putVarint64(iv.Maxt)
 
 			_, err = mw.Write(buf.get())
 			if err != nil {
 				return err
 			}
 		}
-	}
+		return nil
+	})
 
 	_, err = f.Write(hash.Sum(nil))
 	if err != nil {
@@ -100,7 +107,7 @@ type Stone struct {
 	intervals Intervals
 }
 
-func readTombstones(dir string) (tombstoneReader, error) {
+func readTombstones(dir string) (memTombstones, error) {
 	b, err := ioutil.ReadFile(filepath.Join(dir, tombstoneFilename))
 	if err != nil {
 		return nil, err
@@ -131,7 +138,8 @@ func readTombstones(dir string) (tombstoneReader, error) {
 		return nil, errors.New("checksum did not match")
 	}
 
-	stonesMap := newEmptyTombstoneReader()
+	stonesMap := memTombstones{}
+
 	for d.len() > 0 {
 		k := d.uvarint64()
 		mint := d.varint64()
@@ -143,28 +151,36 @@ func readTombstones(dir string) (tombstoneReader, error) {
 		stonesMap.add(k, Interval{mint, maxt})
 	}
 
-	return newTombstoneReader(stonesMap), nil
+	return stonesMap, nil
 }
 
-type tombstoneReader map[uint64]Intervals
+type memTombstones map[uint64]Intervals
 
-func newTombstoneReader(ts map[uint64]Intervals) tombstoneReader {
-	return tombstoneReader(ts)
+var emptyTombstoneReader = memTombstones{}
+
+// EmptyTombstoneReader returns a TombstoneReader that is always empty.
+func EmptyTombstoneReader() TombstoneReader {
+	return emptyTombstoneReader
 }
 
-func newEmptyTombstoneReader() tombstoneReader {
-	return tombstoneReader(make(map[uint64]Intervals))
+func (t memTombstones) Get(ref uint64) (Intervals, error) {
+	return t[ref], nil
 }
 
-func (t tombstoneReader) Get(ref uint64) Intervals {
-	return t[ref]
+func (t memTombstones) Iter(f func(uint64, Intervals) error) error {
+	for ref, ivs := range t {
+		if err := f(ref, ivs); err != nil {
+			return err
+		}
+	}
+	return nil
 }
 
-func (t tombstoneReader) add(ref uint64, itv Interval) {
+func (t memTombstones) add(ref uint64, itv Interval) {
 	t[ref] = t[ref].add(itv)
 }
 
-func (tombstoneReader) Close() error {
+func (memTombstones) Close() error {
 	return nil
 }
 
diff --git a/vendor/github.com/prometheus/tsdb/tsdb.test b/vendor/github.com/prometheus/tsdb/tsdb.test
new file mode 100755
index 0000000000..0cd858d367
Binary files /dev/null and b/vendor/github.com/prometheus/tsdb/tsdb.test differ
diff --git a/vendor/github.com/prometheus/tsdb/wal.go b/vendor/github.com/prometheus/tsdb/wal.go
index b0cea8f09d..72e8bc070b 100644
--- a/vendor/github.com/prometheus/tsdb/wal.go
+++ b/vendor/github.com/prometheus/tsdb/wal.go
@@ -63,11 +63,11 @@ func newWalMetrics(wal *SegmentWAL, r prometheus.Registerer) *walMetrics {
 	m := &walMetrics{}
 
 	m.fsyncDuration = prometheus.NewSummary(prometheus.SummaryOpts{
-		Name: "tsdb_wal_fsync_duration_seconds",
+		Name: "prometheus_tsdb_wal_fsync_duration_seconds",
 		Help: "Duration of WAL fsync.",
 	})
 	m.corruptions = prometheus.NewCounter(prometheus.CounterOpts{
-		Name: "tsdb_wal_corruptions_total",
+		Name: "prometheus_tsdb_wal_corruptions_total",
 		Help: "Total number of WAL corruptions.",
 	})
 
diff --git a/vendor/vendor.json b/vendor/vendor.json
index f3ec812e35..8e61186058 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -782,28 +782,28 @@
 			"revisionTime": "2016-04-11T19:08:41Z"
 		},
 		{
-			"checksumSHA1": "Bty/r75M8kM+GA80eMM5p0cLTi0=",
+			"checksumSHA1": "c3VEi8SL0XmI6BmokMOWrSWmNu8=",
 			"path": "github.com/prometheus/tsdb",
-			"revision": "706602daed1487f7849990678b4ece4599745905",
-			"revisionTime": "2017-11-04T07:45:56Z"
+			"revision": "ad3c4849a99729a9c10a55b3ba4c0ad146d2446a",
+			"revisionTime": "2017-11-23T17:41:24Z"
 		},
 		{
-			"checksumSHA1": "uy6ySJ6EZqof+yMD2wTkYob8BeU=",
+			"checksumSHA1": "C5V8KPHm/gZF0qrNwmIEDdG6rhA=",
 			"path": "github.com/prometheus/tsdb/chunks",
-			"revision": "706602daed1487f7849990678b4ece4599745905",
-			"revisionTime": "2017-11-04T07:45:56Z"
+			"revision": "ad3c4849a99729a9c10a55b3ba4c0ad146d2446a",
+			"revisionTime": "2017-11-23T17:41:24Z"
 		},
 		{
 			"checksumSHA1": "7RhNAVcmDmLFqn9nWiudT0B76f8=",
 			"path": "github.com/prometheus/tsdb/fileutil",
-			"revision": "706602daed1487f7849990678b4ece4599745905",
-			"revisionTime": "2017-11-04T07:45:56Z"
+			"revision": "ad3c4849a99729a9c10a55b3ba4c0ad146d2446a",
+			"revisionTime": "2017-11-23T17:41:24Z"
 		},
 		{
 			"checksumSHA1": "zhmlvc322RH1L3l9DaA9d/HVVWs=",
 			"path": "github.com/prometheus/tsdb/labels",
-			"revision": "706602daed1487f7849990678b4ece4599745905",
-			"revisionTime": "2017-11-04T07:45:56Z"
+			"revision": "ad3c4849a99729a9c10a55b3ba4c0ad146d2446a",
+			"revisionTime": "2017-11-23T17:41:24Z"
 		},
 		{
 			"checksumSHA1": "5SYLEhADhdBVZAGPVHWggQl7H8k=",
diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index 825e8db729..238ba8ff6e 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -380,7 +380,11 @@ func (api *API) series(r *http.Request) (interface{}, *apiError) {
 	var set storage.SeriesSet
 
 	for _, mset := range matcherSets {
-		set = storage.DeduplicateSeriesSet(set, q.Select(mset...))
+		s, err := q.Select(mset...)
+		if err != nil {
+			return nil, &apiError{errorExec, err}
+		}
+		set = storage.DeduplicateSeriesSet(set, s)
 	}
 
 	metrics := []labels.Labels{}
@@ -517,7 +521,12 @@ func (api *API) remoteRead(w http.ResponseWriter, r *http.Request) {
 			}
 		}
 
-		resp.Results[i], err = remote.ToQueryResult(querier.Select(filteredMatchers...))
+		set, err := querier.Select(filteredMatchers...)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		resp.Results[i], err = remote.ToQueryResult(set)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
diff --git a/web/federate.go b/web/federate.go
index 7597f6ddbf..43028a3ac8 100644
--- a/web/federate.go
+++ b/web/federate.go
@@ -75,7 +75,13 @@ func (h *Handler) federation(w http.ResponseWriter, req *http.Request) {
 	var set storage.SeriesSet
 
 	for _, mset := range matcherSets {
-		set = storage.DeduplicateSeriesSet(set, q.Select(mset...))
+		s, err := q.Select(mset...)
+		if err != nil {
+			federationErrors.Inc()
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		set = storage.DeduplicateSeriesSet(set, s)
 	}
 	if set == nil {
 		return