Why JPA/Hibernate is not performing batching?

Question

My Entity class looks as follows :

@Entity
class Entity {

    private UUID id;
    private String name;


    // normal getters and setters

    @PrePersist
    public void init(){
        if(id == null){
            setId(UUID.randomUUID());
        }
    }

In my persistence.xml, I have following :-

    <property name="hibernate.jdbc.batch_size" value="30"/>
    <property name="hibernate.order_inserts" value="true"/>
    <property name="hibernate.order_updates" value="true"/>

Within a single transaction, I am calling "entityManager.persist(myEntity)" inside a for loop. The exact number of iterations may vary across multiple runs.

In my logging configuration I have following,

<logger category="org.hibernate.jdbc.BatchingBatcher">
    <level name="DEBUG"/>
</logger>
<logger category="org.hibernate.jdbc.AbstractBatcher">
    <level name="DEBUG"/>
</logger>
<logger category="org.hibernate.persister.entity.AbstractEntityPersister">
    <level name="DEBUG"/>
</logger>

However, in the server's log, I can not find any evidence of any sort of batching being performed during insert. I am using Hibernate as a JPA provider.

Any idea what am I doing wrong here ?