X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/e028e5daadb83ef695b7e0b1ef6bd45eef4cfc29..bc816b50fc16182fef2f5d17ffd61578432e83c3:/services/keepstore/azure_blob_volume.go

diff --git a/services/keepstore/azure_blob_volume.go b/services/keepstore/azure_blob_volume.go
index 7545e52e86..657c3151ca 100644
--- a/services/keepstore/azure_blob_volume.go
+++ b/services/keepstore/azure_blob_volume.go
@@ -122,7 +122,7 @@ func (v *AzureBlobVolume) Get(loc string) ([]byte, error) {
 	var deadline time.Time
 	haveDeadline := false
 	buf, err := v.get(loc)
-	for err == nil && len(buf) == 0 && loc[:32] != "d41d8cd98f00b204e9800998ecf8427e" {
+	for err == nil && len(buf) == 0 && loc != "d41d8cd98f00b204e9800998ecf8427e" {
 		// Seeing a brand new empty block probably means we're
 		// in a race with CreateBlob, which under the hood
 		// (apparently) does "CreateEmpty" and "CommitData"
@@ -134,38 +134,34 @@ func (v *AzureBlobVolume) Get(loc string) ([]byte, error) {
 				break
 			}
 			deadline = t.Add(azureWriteRaceInterval)
+			if time.Now().After(deadline) {
+				break
+			}
+			log.Printf("Race? Block %s is 0 bytes, %s old. Polling until %s", loc, time.Since(t), deadline)
 			haveDeadline = true
-		}
-		if time.Now().After(deadline) {
+		} else if time.Now().After(deadline) {
 			break
 		}
 		bufs.Put(buf)
 		time.Sleep(azureWriteRacePollTime)
 		buf, err = v.get(loc)
 	}
+	if haveDeadline {
+		log.Printf("Race ended with len(buf)==%d", len(buf))
+	}
 	return buf, err
 }
 
 func (v *AzureBlobVolume) get(loc string) ([]byte, error) {
 	rdr, err := v.bsClient.GetBlob(v.containerName, loc)
 	if err != nil {
-		if strings.Contains(err.Error(), "404 Not Found") {
-			// "storage: service returned without a response body (404 Not Found)"
-			return nil, os.ErrNotExist
-		}
-		return nil, err
-	}
-	switch err := err.(type) {
-	case nil:
-	default:
-		log.Printf("ERROR IN Get(): %T %#v", err, err)
-		return nil, err
+		return nil, v.translateError(err)
 	}
 	defer rdr.Close()
 	buf := bufs.Get(BlockSize)
 	n, err := io.ReadFull(rdr, buf)
 	switch err {
-	case io.EOF, io.ErrUnexpectedEOF:
+	case nil, io.EOF, io.ErrUnexpectedEOF:
 		return buf[:n], nil
 	default:
 		bufs.Put(buf)
@@ -176,7 +172,7 @@ func (v *AzureBlobVolume) get(loc string) ([]byte, error) {
 func (v *AzureBlobVolume) Compare(loc string, expect []byte) error {
 	rdr, err := v.bsClient.GetBlob(v.containerName, loc)
 	if err != nil {
-		return err
+		return v.translateError(err)
 	}
 	defer rdr.Close()
 	return compareReaderWithBuf(rdr, expect, loc[:32])
@@ -279,3 +275,17 @@ func (v *AzureBlobVolume) Writable() bool {
 func (v *AzureBlobVolume) Replication() int {
 	return v.replication
 }
+
+// If possible, translate an Azure SDK error to a recognizable error
+// like os.ErrNotExist.
+func (v *AzureBlobVolume) translateError(err error) error {
+	switch {
+	case err == nil:
+		return err
+	case strings.Contains(err.Error(), "404 Not Found"):
+		// "storage: service returned without a response body (404 Not Found)"
+		return os.ErrNotExist
+	default:
+		return err
+	}
+}