From a4700707b386447b85ed112c195efd5648ae999f Mon Sep 17 00:00:00 2001
From: Chao Xu <xuchao@google.com>
Date: Fri, 30 Oct 2015 15:32:44 -0700
Subject: [PATCH] change the "too old resource version" error from
 InternalError to 410 Gone.

---
 docs/devel/api-conventions.md |  4 ++++
 pkg/api/errors/errors.go      | 10 ++++++++++
 pkg/api/unversioned/types.go  |  5 +++++
 pkg/storage/watch_cache.go    |  2 +-
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/docs/devel/api-conventions.md b/docs/devel/api-conventions.md
index cf389231a3e..9a71fe1c753 100644
--- a/docs/devel/api-conventions.md
+++ b/docs/devel/api-conventions.md
@@ -547,6 +547,10 @@ The following HTTP status codes may be returned by the API.
   * * If updating an existing resource:
       * See `Conflict` from the `status` response section below on how to retrieve more information about the nature of the conflict.
       * GET and compare the fields in the pre-existing object, merge changes (if still valid according to preconditions), and retry with the updated request (including `ResourceVersion`).
+* `410 StatusGone`
+  * Indicates that the item is no longer available at the server and no forwarding address is known.
+  * Suggested client recovery behavior
+    * Do not retry. Fix the request.
 * `422 StatusUnprocessableEntity`
   * Indicates that the requested create or update operation cannot be completed due to invalid data provided as part of the request.
   * Suggested client recovery behavior
diff --git a/pkg/api/errors/errors.go b/pkg/api/errors/errors.go
index 8f1fdb965b2..43c3e3ef73f 100644
--- a/pkg/api/errors/errors.go
+++ b/pkg/api/errors/errors.go
@@ -158,6 +158,16 @@ func NewConflict(kind, name string, err error) error {
 	}}
 }
 
+// NewGone returns an error indicating the item no longer available at the server and no forwarding address is known.
+func NewGone(message string) error {
+	return &StatusError{unversioned.Status{
+		Status:  unversioned.StatusFailure,
+		Code:    http.StatusGone,
+		Reason:  unversioned.StatusReasonGone,
+		Message: message,
+	}}
+}
+
 // NewInvalid returns an error indicating the item is invalid and cannot be processed.
 func NewInvalid(kind, name string, errs fielderrors.ValidationErrorList) error {
 	causes := make([]unversioned.StatusCause, 0, len(errs))
diff --git a/pkg/api/unversioned/types.go b/pkg/api/unversioned/types.go
index c90bf296571..eeab163fc87 100644
--- a/pkg/api/unversioned/types.go
+++ b/pkg/api/unversioned/types.go
@@ -162,6 +162,11 @@ const (
 	// Status code 409
 	StatusReasonConflict StatusReason = "Conflict"
 
+	// StatusReasonGone means the item is no longer available at the server and no
+	// forwarding address is known.
+	// Status code 410
+	StatusReasonGone StatusReason = "Gone"
+
 	// StatusReasonInvalid means the requested create or update operation cannot be
 	// completed due to invalid data provided as part of the request. The client may
 	// need to alter the request. When set, the client may use the StatusDetails
diff --git a/pkg/storage/watch_cache.go b/pkg/storage/watch_cache.go
index 1b376feec1a..475f8b71f38 100644
--- a/pkg/storage/watch_cache.go
+++ b/pkg/storage/watch_cache.go
@@ -266,7 +266,7 @@ func (w *watchCache) GetAllEventsSinceThreadUnsafe(resourceVersion uint64) ([]wa
 		return result, nil
 	}
 	if resourceVersion < oldest {
-		return nil, errors.NewInternalError(fmt.Errorf("too old resource version: %d (%d)", resourceVersion, oldest))
+		return nil, errors.NewGone(fmt.Sprintf("too old resource version: %d (%d)", resourceVersion, oldest))
 	}
 
 	// Binary seatch the smallest index at which resourceVersion is not smaller than