Code hacks

Inject a retryable error in an UPDATE statement on a marked row

Add the following snippet above https://github.com/cockroachdb/cockroach/blob/ef7138bc3fd7261ac40f84762c87f45846f41fe4/cli/start.go#L171

+       // !!!
+       restarted := false
+       cliContext.TestingKnobs.StoreTestingKnobs.TestingCommandFilter =
+               func(args storageutils.FilterArgs) *roachpb.Error {
+                       switch req := args.Req.(type) {
+                       case *roachpb.PutRequest:
+                               if bytes.Contains(req.Value.RawBytes, []byte("marker")) && !restarted {
+                                       log.Infof("!!! injecting retry error")
+                                       restarted = true
+                                       return roachpb.NewErrorWithTxn(
+                                               roachpb.NewTransactionRetryError(), args.Hdr.Txn)
+                               }
+                       }
+                       return nil
+               }