Improve concurrent save/insert optimistic locking [DATACOUCH-224]

[spring-projects-issues]

Anastasiia Smirnova opened DATACOUCH-224 and commented

Follow-up on DATACOUCH-212. While the former has been resolved in its basic form, Aloren has raised concerns that the case of multiple concurrent saves (and even inserts) has not, as no OptimisticLockingException is raised in such a case

---

Affects: 2.1.1 (Hopper SR1)

Issue Links:

• DATACOUCH-212 Optimistic Locking is not working when using Repository save method
  ("depends on")

Referenced from: commits c6b5ecc, 811c024

Backported to: 2.1.2 (Hopper SR2)

[spring-projects-issues]

Eduard Dudar commented

This change introduced some unexpected consequences as for the patch version. Documents that were routed to upsert branch of SAVE operation before are routed to insert (there's versionProperty but there's no version value) now and fail because of key duplication

[spring-projects-issues]

Simon Baslé commented

The assumption is that if you're using an @Version annotated property, you want CAS. So either the document doesn't previously exists, in which case you cannot have a version, and that translates to an insert, or you want to update an existing entity, in which case you want CAS and thus should provide a version.

If you don't want insert+CAS, but rather upsert, then you probably don't need a version property?

[spring-projects-issues]

Eduard Dudar commented

That's true, in my use case all CB accessors produce consistent result on a particular key at a given time so even when one of them updates document the rest are fine to do nothing/overwrite it. I'm not questioning the change itself, it looks good and proper. My point is that replacement of upsert with insert is restrictive and so potentially breaking as it was in my case

[spring-projects-issues]

Simon Baslé commented

So do you think it should be better documented somewhere as a breaking change? (not sure where though, I'm open to suggestions ;) )
Did you have anything else in mind to improve the situation?

[spring-projects-issues]

Eduard Dudar commented

I think ideally changes like this is better to defer until next minor release at least such is upcoming 2.2. As far as documentation at http://docs.spring.io/spring-data/couchbase/docs/2.1.2.RELEASE/reference/html/ has no section about changes it might be beneficially to add notes to https://github.com/spring-projects/spring-data-couchbase/releases? Or add such section to official docs if github is for code only