reorder tablet checks in vtgate tablet gateway

Signed-off-by: austenLacy <[email protected]>

go/vt/vtgate/buffer/buffer.go

@@ -67,7 +67,7 @@ const (
 type RetryDoneFunc context.CancelFunc
 
 const (
-	ClusterEventReshardingInProgress = "current keyspace is being resharded"
+	ClusterEventReshardingInProgress = "current keyspace is potentially being resharded"
 	ClusterEventReparentInProgress   = "primary is not serving, there may be a reparent operation in progress"
 	ClusterEventMoveTables           = "disallowed due to rule"
 )

go/vt/vtgate/tabletgateway.go

@@ -283,22 +283,24 @@ func (gw *TabletGateway) withRetry(ctx context.Context, target *querypb.Target,
 			// if we have a keyspace event watcher, check if the reason why our primary is not available is that it's currently being resharded
 			// or if a reparent operation is in progress.
 			if kev := gw.kev; kev != nil {
-				if kev.TargetIsBeingResharded(ctx, target) {
-					log.V(2).Infof("current keyspace is being resharded, retrying: %s: %s", target.Keyspace, debug.Stack())
-					err = vterrors.Errorf(vtrpcpb.Code_CLUSTER_EVENT, buffer.ClusterEventReshardingInProgress)
-					continue
-				}
 				primary, notServing := kev.PrimaryIsNotServing(ctx, target)
 				if notServing {
 					err = vterrors.Errorf(vtrpcpb.Code_CLUSTER_EVENT, buffer.ClusterEventReparentInProgress)
 					continue
 				}
+
 				// if primary is serving, but we initially found no tablet, we're in an inconsistent state
 				// we then retry the entire loop
 				if primary != nil {
 					err = vterrors.Errorf(vtrpcpb.Code_UNAVAILABLE, "inconsistent state detected, primary is serving but initially found no available tablet")
 					continue
 				}
+
+				if kev.TargetIsBeingResharded(ctx, target) {
+					log.V(2).Infof("current keyspace is potentally being resharded, retrying: %s: %s", target.Keyspace, debug.Stack())
+					err = vterrors.Errorf(vtrpcpb.Code_CLUSTER_EVENT, buffer.ClusterEventReshardingInProgress)
+					continue
+				}
 			}
 
 			// fail fast if there is no tablet