Unexpected errors with "hibernate.order_inserts=true"

[DudekJakub]

Describe the bug

Hello everybody

We were debugging our PROD incident where we were getting errors like:

• ERROR 500: {"details":"Error id cff13a4b-adf8-4ca9-92af-20ceb5a21bf2-1, org.hibernate.HibernateException: java.util.ConcurrentModificationException","stack":"org.hibernate.HibernateException: java.util.ConcurrentModificationException

• ERROR 500: {"details":"Error id cff13a4b-adf8-4ca9-92af-20ceb5a21bf2-2, org.hibernate.HibernateException: java.lang.NullPointerException: Cannot invoke "java.util.List.size()" because "this.batchParamValues" is null"

• ERROR 500: {"details":"Error id cff13a4b-adf8-4ca9-92af-20ceb5a21bf2-3, org.hibernate.HibernateException: java.lang.NullPointerException: Cannot invoke "java.util.Collection.toArray()" because "c" is null"

We were able to create reproducer:
https://github.com/DudekJakub/hibernate-issue-reproducer

Probably it is connected to below:
Enhance defaults in Hibernate ORM issue:
#41698

Zulip chat:
https://hibernate.zulipchat.com/#narrow/channel/132096-hibernate-user/topic/NullPointerExceptions.20in.20hibernate.20reactive/with/542244770

We understand that property hibernate.order_inserts is unsupported in Quarkus but recommended in hibernate.

We've seen that there is ongoing work on Panache2 so we just wanted to leave reproducer since those errors are difficult to invoke without heavy load.

Expected behavior

No response

Actual behavior

No response

How to Reproduce?

No response

Output of uname -a or ver

No response

Output of java -version

21.0.7

Quarkus version or git rev

3.28.2

Build tool (ie. output of mvnw --version or gradlew --version)

gradle-9.1.0

Additional information

No response

[quarkus-bot]

/cc @gsmet (hibernate-orm)

[yrodiere]

Hey,

hibernate.order_inserts is known to be buggy, which is why it's not yet enabled by default in Quarkus.

That being said, I was having trouble finding out what the bugs were exactly, so thank you for providing a reproducer -- hopefully we'll be able to track down at least some of the problems.

In the meantime, the workaround is to just not use this property. Performance will degrade, but that seems better than errors.

We understand that property hibernate.order_inserts is unsupported in Quarkus but recommended in hibernate.

I'm only now learning it's recommended in Hibernate. Can you point me to where you found that information?

[gsmet]

My understanding is that while order_inserts is buggy from a data perspective, I wouldn’t have expected NPEs popping up.

[yrodiere]

My understanding is that while order_inserts is buggy from a data perspective, I wouldn’t have expected NPEs popping up.

That definitely is in the scope of "buggy".

Let's be clear: I'm not trying to get away from fixing this. I'm saying this feature is not one that can be relied on at the moment, because it is... buggy.

[yrodiere]

Created https://hibernate.atlassian.net/browse/HHH-19900 to track this.

... and https://hibernate.atlassian.net/browse/HHH-19901 to regroup quite a few other problems that I found.

[adampoplawski]

Hello
Our intention was to mostly share reproducer so you have "testing tool" since it took as veeeeeery long time to be able to invoke it locally :)

We will also deploy today without this flag and see if we would get this error again on prod. Without this flag we were not getting this error from shared reproducer