Updates and indexing used to be single-threaded. A while ago (maybe in Solr 6.x?), a bunch of locking was removed so that indexing could use multiple CPUs. That is probably what you are seeing.
I don’t think Solr has ever guaranteed ordering for updates, even if it happened to work. Maybe use a real-time get before the update to check whether the document is really there? That should be pretty fast. wunder Walter Underwood wun...@wunderwood.org http://observer.wunderwood.org/ (my blog) > On Sep 25, 2023, at 9:53 AM, Dmitri Maziuk <dmitri.maz...@gmail.com> wrote: > > 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 >
