How Project Leyden brought a new perspective

[giscus[bot]]

How Project Leyden brought a new perspective

Quarkus: Supersonic Subatomic Java

https://quarkus.io/blog/leyden-1/

[jetztgradnet]

Cool stuff, thanks for sharing!

Regarding timezones: how about an option to only ever use UTC for specific cases? When not actually working with timestamps are no need to use specific timezones (e.g. just for log output), only using UTC might (sometimes) be sufficient.

[gsmet]

Thanks! While you're technically true, I pondered a lot if we should go this way but I think it would be a bad idea. Logs are things you might have to read in a critical situation and it might be confusing to not have the timestamps in the right time zone.

I think my point was that it might be an area of the JDK that needs improving. I'm not sure it's feasible given the size of the timezone database but GraalVM might have interesting tricks in this area.

[verhasi]

Very interesting details, actually not the flamegraphs motivated to come here ;), thanks for sharing.

Regarding the Hibernate ORM it is not clear what you mean on

Hopefully, we’ll be able to improve this soon.

Does the https://github.com/hibernate/hibernate-orm/tree/main/tooling/metamodel-generator solves this issue, does not it? May be I am missing some important point to figure out. Please help me to understand.

regards,
István

[gsmet]

Hey!

So the problem is not with the metamodel used for querying, but with the metamodel Hibernate ORM builds for itself: scanning the classes, the annotations, detecting entities, relations... This is something that could be done at build time and somehow serialized and that's one of the end goals of the https://github.com/hibernate/hibernate-models project.

Now, what makes it even harder is that some elements of the model used to depend on information you would obtain from the database itself on connection... which is not something you can do at build time (as you won't connect to your production database at build time).

This is a lot of work, the hibernate-models projects already went us quite far, but there is still a ton of remaining work to be able to build the Hibernate ORM metamodel at build time, serialize it and include it in the jar/native executable, and deserialize it at runtime.

I hope it clarified things a bit :)