Correctly close querier on error, revendor tsdb

promql/engine.go

@@ -345,10 +345,16 @@ func (ng *Engine) execEvalStmt(ctx context.Context, query *query, s *EvalStmt) (
 	prepareTimer.Stop()
 	queryPrepareTime.Observe(prepareTimer.ElapsedTime().Seconds())
 
+	// XXX(fabxc): the querier returned by populateIterators might be instantiated
+	// we must not return without closing irrespective of the error.
+	// TODO: make this semantically saner.
+	if querier != nil {
+		defer querier.Close()
+	}
+
 	if err != nil {
 		return nil, err
 	}
-	defer querier.Close()
 
 	evalTimer := query.stats.GetTimer(stats.InnerEvalTime).Start()
 	// Instant evaluation.

vendor/github.com/fabxc/tsdb/db.go

@@ -369,10 +369,7 @@ func (db *DB) reloadBlocks() error {
 			}
 			heads = append(heads, b.(*headBlock))
 		} else {
-			if ok && meta.ULID != b.Meta().ULID {
-				if err := b.Close(); err != nil {
-					return err
-				}
+			if !ok || meta.ULID != b.Meta().ULID {
 				b, err = newPersistedBlock(dirs[i])
 				if err != nil {
 					return errors.Wrapf(err, "open persisted block %s", dirs[i])
@@ -385,7 +382,7 @@ func (db *DB) reloadBlocks() error {
 	}
 
 	for seq, b := range db.seqBlocks {
-		if _, ok := seqBlocks[seq]; !ok {
+		if nb, ok := seqBlocks[seq]; !ok || nb != b {
 			if err := b.Close(); err != nil {
 				return errors.Wrapf(err, "closing removed block %d", b.Meta().Sequence)
 			}

vendor/github.com/fabxc/tsdb/wal.go

@@ -299,6 +299,8 @@ func (w *WAL) entry(et WALEntryType, flag byte, buf []byte) error {
 		sz    = int64(6 + 4 + len(buf))
 		newsz = w.curN + sz
 	)
+	// XXX(fabxc): this currently cuts a new file whenever the WAL was newly opened.
+	// Probably fine in general but may yield a lot of short files in some cases.
 	if w.cur == nil || w.curN > w.segmentSize || newsz > w.segmentSize && sz <= w.segmentSize {
 		if err := w.cut(); err != nil {
 			return err
@@ -431,6 +433,8 @@ func NewWALReader(rs ...io.ReadCloser) *WALReader {
 }
 
 // At returns the last decoded entry of labels or samples.
+// The returned slices are only valid until the next call to Next(). Their elements
+// have to be copied to preserve them.
 func (r *WALReader) At() ([]labels.Labels, []refdSample) {
 	return r.labels, r.samples
 }

vendor/vendor.json

@@ -368,10 +368,10 @@
 			"revisionTime": "2016-09-30T00:14:02Z"
 		},
 		{
-			"checksumSHA1": "Aj4Cn1RClamxluIri/LQMnK/yB4=",
+			"checksumSHA1": "hnxY08GfzanNSvD8vjz/wSWnwmk=",
 			"path": "github.com/fabxc/tsdb",
-			"revision": "ca1bc920b795cfc670002e7643471b0277e79a9b",
-			"revisionTime": "2017-03-08T15:54:13Z"
+			"revision": "32c32013a6d2a8ee5fb231d3f3cb5538128650d2",
+			"revisionTime": "2017-03-09T14:40:13Z"
 		},
 		{
 			"checksumSHA1": "uVzWuLvF646YjiKomsc2CR1ua58=",