Use fallback if urls are not found

weed/filer/stream.go

@@ -69,14 +69,14 @@ func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writ
 	fileId2Url := make(map[string][]string)
 
 	for _, chunkView := range chunkViews {
-
 		urlStrings, err := masterClient.GetLookupFileIdFunction()(chunkView.FileId)
 		if err != nil {
 			glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err)
 			return err
 		} else if len(urlStrings) == 0 {
-			glog.Errorf("operation LookupFileId %s failed, err: urls not found", chunkView.FileId)
-			return fmt.Errorf("operation LookupFileId %s failed, err: urls not found", chunkView.FileId)
+			errUrlNotFound := fmt.Errorf("operation LookupFileId %s failed, err: urls not found", chunkView.FileId)
+			glog.Error(errUrlNotFound)
+			return errUrlNotFound
 		}
 		fileId2Url[chunkView.FileId] = urlStrings
 	}

weed/wdclient/masterclient.go

@@ -2,6 +2,7 @@ package wdclient
 
 import (
 	"context"
+	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/stats"
 	"math/rand"
 	"time"
@@ -44,7 +45,7 @@ func (mc *MasterClient) GetLookupFileIdFunction() LookupFileIdFunctionType {
 
 func (mc *MasterClient) LookupFileIdWithFallback(fileId string) (fullUrls []string, err error) {
 	fullUrls, err = mc.vidMap.LookupFileId(fileId)
-	if err == nil {
+	if err == nil && len(fullUrls) > 0 {
 		return
 	}
 	err = pb.WithMasterClient(false, mc.currentMaster, mc.grpcDialOption, func(client master_pb.SeaweedClient) error {
@@ -52,7 +53,7 @@ func (mc *MasterClient) LookupFileIdWithFallback(fileId string) (fullUrls []stri
 			VolumeOrFileIds: []string{fileId},
 		})
 		if err != nil {
-			return err
+			return fmt.Errorf("LookupVolume failed: %v", err)
 		}
 		for vid, vidLocation := range resp.VolumeIdLocations {
 			for _, vidLoc := range vidLocation.Locations {
@@ -65,7 +66,6 @@ func (mc *MasterClient) LookupFileIdWithFallback(fileId string) (fullUrls []stri
 				fullUrls = append(fullUrls, "http://"+loc.Url+"/"+fileId)
 			}
 		}
-
 		return nil
 	})
 	return