TSM: TSMReader.Close blocks until reads complete

coordinator/points_writer.go

@@ -2,6 +2,7 @@ package coordinator
 
 import (
 	"errors"
+	"fmt"
 	"sort"
 	"sync"
 	"sync/atomic"
@@ -308,7 +309,11 @@ func (w *PointsWriter) WritePointsPrivileged(database, retentionPolicy string, c
 	ch := make(chan error, len(shardMappings.Points))
 	for shardID, points := range shardMappings.Points {
 		go func(shard *meta.ShardInfo, database, retentionPolicy string, points []models.Point) {
-			ch <- w.writeToShard(shard, database, retentionPolicy, points)
+			err := w.writeToShard(shard, database, retentionPolicy, points)
+			if err == tsdb.ErrShardDeletion {
+				err = tsdb.PartialWriteError{Reason: fmt.Sprintf("shard %d is pending deletion", shard.ID), Dropped: len(points)}
+			}
+			ch <- err
 		}(shardMappings.Shards[shardID], database, retentionPolicy, points)
 	}
 

tsdb/engine/tsm1/file_store.go

@@ -530,7 +530,10 @@ func (f *FileStore) Close() error {
 	defer f.mu.Unlock()
 
 	for _, file := range f.files {
-		file.Close()
+		err := file.Close()
+		if err != nil {
+			return err
+		}
 	}
 
 	f.lastFileStats = nil

tsdb/engine/tsm1/reader.go

@@ -25,7 +25,8 @@ var nilOffset = []byte{255, 255, 255, 255}
 // TSMReader is a reader for a TSM file.
 type TSMReader struct {
 	// refs is the count of active references to this reader.
-	refs int64
+	refs   int64
+	refsWG sync.WaitGroup
 
 	mu sync.RWMutex
 
@@ -398,13 +399,11 @@ func (t *TSMReader) Type(key []byte) (byte, error) {
 
 // Close closes the TSMReader.
 func (t *TSMReader) Close() error {
+	t.refsWG.Wait()
+
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
-	if t.InUse() {
-		return ErrFileInUse
-	}
-
 	if err := t.accessor.close(); err != nil {
 		return err
 	}
@@ -417,13 +416,15 @@ func (t *TSMReader) Close() error {
 // there are no more references.
 func (t *TSMReader) Ref() {
 	atomic.AddInt64(&t.refs, 1)
+	t.refsWG.Add(1)
 }
 
 // Unref removes a usage record of this TSMReader.  If the Reader was closed
 // by another goroutine while there were active references, the file will
 // be closed and remove
 func (t *TSMReader) Unref() {
 	atomic.AddInt64(&t.refs, -1)
+	t.refsWG.Done()
 }
 
 // InUse returns whether the TSMReader currently has any active references.
@@ -455,7 +456,10 @@ func (t *TSMReader) remove() error {
 	}
 
 	if path != "" {
-		os.RemoveAll(path)
+		err := os.RemoveAll(path)
+		if err != nil {
+			return err
+		}
 	}
 
 	if err := t.tombstoner.Delete(); err != nil {

tsdb/engine/tsm1/reader_test.go

@@ -1828,10 +1828,6 @@ func TestTSMReader_References(t *testing.T) {
 
 	r.Ref()
 
-	if err := r.Close(); err != ErrFileInUse {
-		t.Fatalf("expected error closing reader: %v", err)
-	}
-
 	if err := r.Remove(); err != ErrFileInUse {
 		t.Fatalf("expected error removing reader: %v", err)
 	}

tsdb/store.go

@@ -31,6 +31,8 @@ var (
 	ErrShardNotFound = fmt.Errorf("shard not found")
 	// ErrStoreClosed is returned when trying to use a closed Store.
 	ErrStoreClosed = fmt.Errorf("store is closed")
+	// ErrShardDeletion is returned when trying to create a shard that is being deleted
+	ErrShardDeletion = errors.New("shard is being deleted")
 )
 
 // Statistics gathered by the store.
@@ -523,7 +525,7 @@ func (s *Store) CreateShard(database, retentionPolicy string, shardID uint64, en
 	// Shard may be undergoing a pending deletion. While the shard can be
 	// recreated, it must wait for the pending delete to finish.
 	if _, ok := s.pendingShardDeletes[shardID]; ok {
-		return fmt.Errorf("shard %d is pending deletion and cannot be created again until finished", shardID)
+		return ErrShardDeletion
 	}
 
 	// Create the db and retention policy directories if they don't exist.