Yeah, thanks a lot for reaching out, @Stuart Douglas. It was a good opportunity for us to look into this kind of improvements and, thanks to Guillaume's work, things have nicely improved in HV 6.0.1. We also got some more ideas which we'll look into for upcoming releases.

Thanks, this was not an urgent issue, just something that I noticed that I thought would be good for someone to look at (as reduction of memory usage in general will be a focus for us).

@Stuart Douglas I don't know how urgent this issue is to you.

We have released HV 6.0.1.Final and it will be a clear improvement on the version included in WildFly regarding the issue you reported.

If you want to benefit from the improvements, you can use the WildFly patch we have published here:

• For WildFly 10.1.0.Final: http://search.maven.org/remotecontent?filepath=org/hibernate/validator/hibernate-validator-modules/6.0.1.Final/hibernate-validator-modules-6.0.1.Final-wildfly-10.1.0.Final-patch.zip

• For WildFly 11.0.0.Alpha1: http://search.maven.org/remotecontent?filepath=org/hibernate/validator/hibernate-validator-modules/6.0.1.Final/hibernate-validator-modules-6.0.1.Final-wildfly-11.0.0.Alpha1-patch.zip

(we will release a patch for Beta1 with our next minor)

Considering your (lack of) usage of HV in Keycloak, it should be a drop in replacement, I don't expect any issue. We have integration tests running HV 6 on top of WF 10.1 and WF 11.0.

You can apply a patch file automatically when building using the WildFly Maven plugin: https://github.com/hibernate/hibernate-validator/blob/master/integration/pom.xml#L334 .

Btw, quick explanation about why you are experiencing this issue so much: your bean contains a lot of properties and getters (think of RealmEntity for instance) and this is why it eats quite a lot of memory as metadata adds up.

I improved a few things here and there (the BeanMetaDataImpl instance of RealmEntity now takes 65 kB whereas it took 177 kB in your snapshot) but I'm wondering if we shouldn't take more drastic measures.

Will post something on hibernate-dev and add you in cc.

Thanks for the snapshot.

FWIW, there are already some significant improvements in 6 but it looks like we still have some work to do on this front.