No need to set the error_state inside doIndexUpdateActor since:

1. It's useless as in it does not update the IndexObj stored on disk, which means it does not effectively mark the index as in error state
2. If these error got thrown during index building, the MetadataManager will correctly update the on disk IndexObj to reflect the error state. If this error got thrown during updating existing index due to inserting new documents or updating documents, no need to change the state of the index and we can simply reject the insert/update

Author: Xin Dong

src/QLContext.actor.cpp

@@ -353,7 +353,6 @@ struct CompoundIndexPlugin : IndexPlugin, ReferenceCounted<CompoundIndexPlugin>,
 			}
 
 			if (num_new_values > DOCLAYER_KNOBS->MULTI_MULTIKEY_INDEX_MAX) {
-				self->error_state = true;
 				throw multikey_index_cartesian_explosion();
 			}
 
@@ -520,7 +519,6 @@ struct SimpleIndexPlugin : IndexPlugin, ReferenceCounted<SimpleIndexPlugin>, Fas
 						    existing_index_entries.front().arena());
 						if (existingDocId.compare(documentPath[documentPath.size() - 1])) {
 							// existing index points to a different doc id that has the same value, abort.
-							self->error_state = true;
 							throw duplicated_key_field();
 						}
 					}