On 9/25/23 08:24, Shawn Heisey wrote: ...
Solr 4.7 handles this as the customer wants, but Solr 9.1 doesn't.
This sounds like a race condition, are you sure it's Solr doing the ordering and not e.g. the network stack?
What I found is that when the "add" request comes first, 8.11.2 (at least) will create a new -- useless -- document for it. I wish it failed instead.
Dima