[BUG] Retry fetching subworkflow output data on failure

flytepropeller/pkg/controller/controller.go

@@ -324,10 +324,21 @@
 		logger.Errorf(ctx, "failed to initialize Admin client, err :%s", err.Error())
 		return nil, err
 	}
+
+	sCfg := storage.GetConfig()
+	if sCfg == nil {
+		logger.Errorf(ctx, "Storage configuration missing.")
+	}
+
+	store, err := storage.NewDataStore(sCfg, scope.NewSubScope("metastore"))
+	if err != nil {
+		return nil, errors.Wrapf(err, "Failed to create Metadata storage")
+	}
+
 	var launchPlanActor launchplan.FlyteAdmin
 	if cfg.EnableAdminLauncher {
 		launchPlanActor, err = launchplan.NewAdminLaunchPlanExecutor(ctx, adminClient, cfg.DownstreamEval.Duration,
-			launchplan.GetAdminConfig(), scope.NewSubScope("admin_launcher"))
+			launchplan.GetAdminConfig(), scope.NewSubScope("admin_launcher"), store)
 		if err != nil {
 			logger.Errorf(ctx, "failed to create Admin workflow Launcher, err: %v", err.Error())
 			return nil, err
@@ -401,16 +412,6 @@
 
 	flytek8s.DefaultPodTemplateStore.SetDefaultNamespace(podNamespace)
 
-	sCfg := storage.GetConfig()
-	if sCfg == nil {
-		logger.Errorf(ctx, "Storage configuration missing.")
-	}
-
-	store, err := storage.NewDataStore(sCfg, scope.NewSubScope("metastore"))
-	if err != nil {
-		return nil, errors.Wrapf(err, "Failed to create Metadata storage")
-	}
-
 	logger.Info(ctx, "Setting up Catalog client.")
 	catalogClient, err := catalog.NewCatalogClient(ctx, authOpts...)
 	if err != nil {

flytepropeller/pkg/controller/nodes/subworkflow/launchplan/admin.go

@@ -19,6 +19,7 @@ import (
 	stdErr "github.com/flyteorg/flyte/flytestdlib/errors"
 	"github.com/flyteorg/flyte/flytestdlib/logger"
 	"github.com/flyteorg/flyte/flytestdlib/promutils"
+	"github.com/flyteorg/flyte/flytestdlib/storage"
 )
 
 var isRecovery = true
@@ -33,6 +34,7 @@ func IsWorkflowTerminated(p core.WorkflowExecution_Phase) bool {
 type adminLaunchPlanExecutor struct {
 	adminClient service.AdminServiceClient
 	cache       cache.AutoRefresh
+	store       *storage.DataStore
 }
 
 type executionCacheItem struct {
@@ -258,29 +260,39 @@ func (a *adminLaunchPlanExecutor) syncItem(ctx context.Context, batch cache.Batc
 			continue
 		}
 
-		var outputs *core.LiteralMap
+		var outputs = &core.LiteralMap{}
 		// Retrieve potential outputs only when the workflow succeeded.
 		// TODO: We can optimize further by only retrieving the outputs when the workflow has output variables in the
 		// 	interface.
 		if res.GetClosure().GetPhase() == core.WorkflowExecution_SUCCEEDED {
 			execData, err := a.adminClient.GetExecutionData(ctx, &admin.WorkflowExecutionGetDataRequest{
 				Id: &exec.WorkflowExecutionIdentifier,
 			})
+			if err != nil || execData.GetFullOutputs() == nil || execData.GetFullOutputs().GetLiterals() == nil {
+				outputURI := res.GetClosure().GetOutputs().GetUri()
+				// attempt remote storage read on GetExecutionData failure
+				if outputURI != "" {
+					err = a.store.ReadProtobuf(ctx, storage.DataReference(outputURI), outputs)
+					if err != nil {
+						logger.Errorf(ctx, "Failed to read outputs from URI [%s] with err: %v", outputURI, err)
+					}
+				}
+				if err != nil {
+					resp = append(resp, cache.ItemSyncResponse{
+						ID: obj.GetID(),
+						Item: executionCacheItem{
+							WorkflowExecutionIdentifier: exec.WorkflowExecutionIdentifier,
+							SyncError:                   err,
+						},
+						Action: cache.Update,
+					})
+
+					continue
+				}
 
-			if err != nil {
-				resp = append(resp, cache.ItemSyncResponse{
-					ID: obj.GetID(),
-					Item: executionCacheItem{
-						WorkflowExecutionIdentifier: exec.WorkflowExecutionIdentifier,
-						SyncError:                   err,
-					},
-					Action: cache.Update,
-				})
-
-				continue
+			} else {
+				outputs = execData.GetFullOutputs()
 			}
-
-			outputs = execData.GetFullOutputs()
 		}
 
 		// Update the cache with the retrieved status
@@ -299,9 +311,10 @@ func (a *adminLaunchPlanExecutor) syncItem(ctx context.Context, batch cache.Batc
 }
 
 func NewAdminLaunchPlanExecutor(_ context.Context, client service.AdminServiceClient,
-	syncPeriod time.Duration, cfg *AdminConfig, scope promutils.Scope) (FlyteAdmin, error) {
+	syncPeriod time.Duration, cfg *AdminConfig, scope promutils.Scope, store *storage.DataStore) (FlyteAdmin, error) {
 	exec := &adminLaunchPlanExecutor{
 		adminClient: client,
+		store:       store,
 	}
 
 	rateLimiter := &workqueue.BucketRateLimiter{Limiter: rate.NewLimiter(rate.Limit(cfg.TPS), cfg.Burst)}