Concurrent edits to a lucene document

Question

I noticed there this this method: https://lucene.apache.org/core/6_1_0/core/org/apache/lucene/index/IndexWriter.html#updateDocument-org.apache.lucene.index.Term-java.lang.Iterable-

So I would first pull out the document, make the change and then use the above method to update via uid. This implies I require external synchronisation if I have concurrent updates.

Or is there another way to do this that I am not aware of?

Answer 1

As written on mentioned above link

The delete and then add are atomic as seen by a reader on the same index.

That means no other thread can observe the modification half-complete, will either see the value before the update, or after the update.

So it is better to do external synchronization for concurrent updates.