Change it to rollback

CHANGELOG.md

@@ -16,7 +16,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Added SubmitPoolAttesterSlashingV2 endpoint.
 - Added SubmitAggregateAndProofsRequestV2 endpoint.
 - Updated the `beacon-chain/monitor` package to Electra. [PR](https://github.com/prysmaticlabs/prysm/pull/14562)
-
+- Add ability to rollback node's internal state during processing.
 ### Changed
 
 - Electra EIP6110: Queue deposit requests changes from consensus spec pr #3818

beacon-chain/blockchain/process_block.go

@@ -76,6 +76,7 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 
 	err := s.cfg.ForkChoiceStore.InsertNode(ctx, cfg.postState, cfg.roblock)
 	if err != nil {
+		s.rollbackBlock(ctx, cfg.roblock.Root())
 		return errors.Wrapf(err, "could not insert block %d to fork choice store", cfg.roblock.Block().Slot())
 	}
 	if err := s.handleBlockAttestations(ctx, cfg.roblock.Block(), cfg.postState); err != nil {
@@ -687,3 +688,15 @@ func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, bl
 	}
 	return err
 }
+
+// In the event of an issue processing a block we rollback changes done to the db and our caches
+// to always ensure that the node's internal state is consistent.
+func (s *Service) rollbackBlock(ctx context.Context, blockRoot [32]byte) {
+	log.Warnf("Rolling back insertion of block with root %#x due to processing error", blockRoot)
+	if err := s.cfg.BeaconDB.DeleteBlock(ctx, blockRoot); err != nil {
+		log.WithError(err).Errorf("Could not delete block with block root %#x", blockRoot)
+	}
+	if err := s.cfg.StateGen.DeleteStateFromCaches(ctx, blockRoot); err != nil {
+		log.WithError(err).Errorf("Could not delete state from caches with block root %#x", blockRoot)
+	}
+}