From 15bc10d5cf99bda13f51be18f40ba033ba87a02a Mon Sep 17 00:00:00 2001
From: Yichao Yang <yichao@temporal.io>
Date: Fri, 26 May 2023 10:08:14 -0700
Subject: [PATCH] Fix mutable state get event error handling (#4396)

---
 common/util.go                                |  6 ++
 .../history/workflow/mutable_state_impl.go    | 66 ++++++++++++-------
 2 files changed, 48 insertions(+), 24 deletions(-)

diff --git a/common/util.go b/common/util.go
index ea3180ee2e8..fb62b323536 100644
--- a/common/util.go
+++ b/common/util.go
@@ -380,6 +380,12 @@ func IsInternalError(err error) bool {
 	return errors.As(err, &internalErr)
 }
 
+// IsNotFoundError checks if the error is a not found error.
+func IsNotFoundError(err error) bool {
+	var notFoundErr *serviceerror.NotFound
+	return errors.As(err, &notFoundErr)
+}
+
 // WorkflowIDToHistoryShard is used to map namespaceID-workflowID pair to a shardID.
 func WorkflowIDToHistoryShard(
 	namespaceID string,
diff --git a/service/history/workflow/mutable_state_impl.go b/service/history/workflow/mutable_state_impl.go
index 9901f8a0d3d..f275cdcc9cf 100644
--- a/service/history/workflow/mutable_state_impl.go
+++ b/service/history/workflow/mutable_state_impl.go
@@ -785,10 +785,13 @@ func (ms *MutableStateImpl) GetActivityScheduledEvent(
 		currentBranchToken,
 	)
 	if err != nil {
-		// do not return the original error
-		// since original error can be of type entity not exists
-		// which can cause task processing side to fail silently
-		return nil, ErrMissingActivityScheduledEvent
+		if common.IsNotFoundError(err) {
+			// do not return the original error
+			// since original error of type NotFound
+			// can cause task processing side to fail silently
+			return nil, ErrMissingActivityScheduledEvent
+		}
+		return nil, err
 	}
 	return event, nil
 }
@@ -865,10 +868,13 @@ func (ms *MutableStateImpl) GetChildExecutionInitiatedEvent(
 		currentBranchToken,
 	)
 	if err != nil {
-		// do not return the original error
-		// since original error can be of type entity not exists
-		// which can cause task processing side to fail silently
-		return nil, ErrMissingChildWorkflowInitiatedEvent
+		if common.IsNotFoundError(err) {
+			// do not return the original error
+			// since original error of type NotFound
+			// can cause task processing side to fail silently
+			return nil, ErrMissingChildWorkflowInitiatedEvent
+		}
+		return nil, err
 	}
 	return event, nil
 }
@@ -908,10 +914,13 @@ func (ms *MutableStateImpl) GetRequesteCancelExternalInitiatedEvent(
 		currentBranchToken,
 	)
 	if err != nil {
-		// do not return the original error
-		// since original error can be of type entity not exists
-		// which can cause task processing side to fail silently
-		return nil, ErrMissingRequestCancelInfo
+		if common.IsNotFoundError(err) {
+			// do not return the original error
+			// since original error of type NotFound
+			// can cause task processing side to fail silently
+			return nil, ErrMissingRequestCancelInfo
+		}
+		return nil, err
 	}
 	return event, nil
 }
@@ -982,10 +991,13 @@ func (ms *MutableStateImpl) GetSignalExternalInitiatedEvent(
 		currentBranchToken,
 	)
 	if err != nil {
-		// do not return the original error
-		// since original error can be of type entity not exists
-		// which can cause task processing side to fail silently
-		return nil, ErrMissingSignalInitiatedEvent
+		if common.IsNotFoundError(err) {
+			// do not return the original error
+			// since original error of type NotFound
+			// can cause task processing side to fail silently
+			return nil, ErrMissingSignalInitiatedEvent
+		}
+		return nil, err
 	}
 	return event, nil
 }
@@ -1020,10 +1032,13 @@ func (ms *MutableStateImpl) GetCompletionEvent(
 		currentBranchToken,
 	)
 	if err != nil {
-		// do not return the original error
-		// since original error can be of type entity not exists
-		// which can cause task processing side to fail silently
-		return nil, ErrMissingWorkflowCompletionEvent
+		if common.IsNotFoundError(err) {
+			// do not return the original error
+			// since original error of type NotFound
+			// can cause task processing side to fail silently
+			return nil, ErrMissingWorkflowCompletionEvent
+		}
+		return nil, err
 	}
 	return event, nil
 }
@@ -1070,10 +1085,13 @@ func (ms *MutableStateImpl) GetStartEvent(
 		currentBranchToken,
 	)
 	if err != nil {
-		// do not return the original error
-		// since original error can be of type entity not exists
-		// which can cause task processing side to fail silently
-		return nil, ErrMissingWorkflowStartEvent
+		if common.IsNotFoundError(err) {
+			// do not return the original error
+			// since original error of type NotFound
+			// can cause task processing side to fail silently
+			return nil, ErrMissingWorkflowStartEvent
+		}
+		return nil, err
 	}
 	return event, nil
 }