idx file sync before compaction

weed/storage/needle_map.go

@@ -30,6 +30,7 @@ type NeedleMapper interface {
 	DeletedCount() int
 	MaxFileKey() NeedleId
 	IndexFileSize() uint64
+	Sync() error
 }
 
 type baseNeedleMapper struct {
@@ -59,3 +60,7 @@ func (nm *baseNeedleMapper) appendToIndexFile(key NeedleId, offset Offset, size
 	_, err := nm.indexFile.Write(bytes)
 	return err
 }
+
+func (nm *baseNeedleMapper) Sync() error {
+	return nm.indexFile.Sync()
+}

weed/storage/volume_vacuum.go

@@ -56,6 +56,9 @@ func (v *Volume) Compact(preallocate int64, compactionBytePerSecond int64) error
 	if err := v.DataBackend.Sync(); err != nil {
 		glog.V(0).Infof("compact fail to sync volume %d", v.Id)
 	}
+	if err := v.nm.Sync(); err != nil {
+		glog.V(0).Infof("compact fail to sync volume idx %d", v.Id)
+	}
 	return v.copyDataAndGenerateIndexFile(filePath+".cpd", filePath+".cpx", preallocate, compactionBytePerSecond)
 }
 
@@ -77,7 +80,10 @@ func (v *Volume) Compact2(preallocate int64, compactionBytePerSecond int64) erro
 	v.lastCompactRevision = v.SuperBlock.CompactionRevision
 	glog.V(3).Infof("creating copies for volume %d ...", v.Id)
 	if err := v.DataBackend.Sync(); err != nil {
-		glog.V(0).Infof("compact2 fail to sync volume %d", v.Id)
+		glog.V(0).Infof("compact2 fail to sync volume dat %d", v.Id)
+	}
+	if err := v.nm.Sync(); err != nil {
+		glog.V(0).Infof("compact2 fail to sync volume idx %d", v.Id)
 	}
 	return copyDataBasedOnIndexFile(filePath+".dat", filePath+".idx", filePath+".cpd", filePath+".cpx", v.SuperBlock, v.Version(), preallocate, compactionBytePerSecond)
 }
@@ -99,9 +105,6 @@ func (v *Volume) CommitCompact() error {
 	glog.V(3).Infof("Got volume %d committing lock...", v.Id)
 	v.nm.Close()
 	if v.DataBackend != nil {
-		if err := v.DataBackend.Sync(); err != nil {
-			glog.V(0).Infof("fail to sync volume %d", v.Id)
-		}
 		if err := v.DataBackend.Close(); err != nil {
 			glog.V(0).Infof("fail to close volume %d", v.Id)
 		}