From 4db2480f472fc6958786ffc95eea96b39fee2d20 Mon Sep 17 00:00:00 2001
From: Robert Raynor <35671663+mooselumph@users.noreply.github.com>
Date: Fri, 29 Mar 2024 18:06:13 -0700
Subject: [PATCH] don't count metadata not found as internal error (#418)

---
 disperser/apiserver/server.go                     | 9 +++++++--
 disperser/apiserver/server_test.go                | 2 +-
 disperser/common/blobstore/blob_metadata_store.go | 7 ++++++-
 disperser/errors.go                               | 3 ++-
 4 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/disperser/apiserver/server.go b/disperser/apiserver/server.go
index 7d38040622..f09da8d3d9 100644
--- a/disperser/apiserver/server.go
+++ b/disperser/apiserver/server.go
@@ -520,7 +520,9 @@ func (s *DispersalServer) GetBlobStatus(ctx context.Context, req *pb.BlobStatusR
 	s.logger.Debug("metadataKey", "metadataKey", metadataKey.String())
 	metadata, err := s.blobStore.GetBlobMetadata(ctx, metadataKey)
 	if err != nil {
-		// TODO: we need to distinguish NOT_FOUND from actual internal error.
+		if errors.Is(err, disperser.ErrMetadataNotFound) {
+			return nil, api.NewInvalidArgError("no metadata found for the requestID")
+		}
 		return nil, api.NewInternalError(fmt.Sprintf("failed to get blob metadata, blobkey: %s", metadataKey.String()))
 	}
 
@@ -650,7 +652,10 @@ func (s *DispersalServer) RetrieveBlob(ctx context.Context, req *pb.RetrieveBlob
 	blobMetadata, err := s.blobStore.GetMetadataInBatch(ctx, batchHeaderHash32, blobIndex)
 	if err != nil {
 		s.logger.Error("Failed to retrieve blob metadata", "err", err)
-		// TODO: we need to distinguish NOT_FOUND from actual internal error.
+		if errors.Is(err, disperser.ErrMetadataNotFound) {
+			s.metrics.IncrementFailedBlobRequestNum(codes.NotFound.String(), "", "RetrieveBlob")
+			return nil, api.NewInvalidArgError("no metadata found for the given batch header hash and blob index")
+		}
 		s.metrics.IncrementFailedBlobRequestNum(codes.Internal.String(), "", "RetrieveBlob")
 		return nil, api.NewInternalError("failed to get blob metadata, please retry")
 	}
diff --git a/disperser/apiserver/server_test.go b/disperser/apiserver/server_test.go
index e0cf81e049..819e8203a5 100644
--- a/disperser/apiserver/server_test.go
+++ b/disperser/apiserver/server_test.go
@@ -350,7 +350,7 @@ func TestRetrieveBlobFailsWhenBlobNotConfirmed(t *testing.T) {
 	// Try to retrieve the blob before it is confirmed
 	_, err = retrieveBlob(t, dispersalServer, requestID, 2)
 	assert.NotNil(t, err)
-	assert.Equal(t, err.Error(), "rpc error: code = Internal desc = failed to get blob metadata, please retry")
+	assert.Equal(t, "rpc error: code = InvalidArgument desc = no metadata found for the given batch header hash and blob index", err.Error())
 
 }
 
diff --git a/disperser/common/blobstore/blob_metadata_store.go b/disperser/common/blobstore/blob_metadata_store.go
index 4a284895ef..5ed56cb38a 100644
--- a/disperser/common/blobstore/blob_metadata_store.go
+++ b/disperser/common/blobstore/blob_metadata_store.go
@@ -61,6 +61,11 @@ func (s *BlobMetadataStore) GetBlobMetadata(ctx context.Context, metadataKey dis
 			Value: metadataKey.MetadataHash,
 		},
 	})
+
+	if item == nil {
+		return nil, fmt.Errorf("%w: metadata not found for key %s", disperser.ErrMetadataNotFound, metadataKey)
+	}
+
 	if err != nil {
 		return nil, err
 	}
@@ -199,7 +204,7 @@ func (s *BlobMetadataStore) GetBlobMetadataInBatch(ctx context.Context, batchHea
 	}
 
 	if len(items) == 0 {
-		return nil, fmt.Errorf("there is no metadata for batch %s and blob index %d", batchHeaderHash, blobIndex)
+		return nil, fmt.Errorf("%w: there is no metadata for batch %s and blob index %d", disperser.ErrMetadataNotFound, batchHeaderHash, blobIndex)
 	}
 
 	if len(items) > 1 {
diff --git a/disperser/errors.go b/disperser/errors.go
index 8681436942..2872dbd100 100644
--- a/disperser/errors.go
+++ b/disperser/errors.go
@@ -3,5 +3,6 @@ package disperser
 import "errors"
 
 var (
-	ErrBlobNotFound = errors.New("blob not found")
+	ErrBlobNotFound     = errors.New("blob not found")
+	ErrMetadataNotFound = errors.New("metadata not found")
 )