Hibernate JPA+mysql: can not disable caching in createNativeQuery - mysql

Question

I am using Hibernate/JPA with mySQL, and because of legacy reasons createNativeQuery at one point. The application works with different servers using the same database, so it should do no caching at all but always show the most recent result. I simulate other servers by changing a value manually in a database-editor, but after a change it always gives old results.
As far as I know I should disable any 2nd level caching (not very important because I do not use any ORM-objects), clear() any 1st level caching, and disable mysql query caching (is already done on database level). Where do I fail, or what do I forget? It drives me crazy.
init(): start of the servlet
entityFactory = Persistence.createEntityManagerFactory("persistence-id");
getEntityManager(): start of each request
destroyEntityManager(); // just in case
entityFactory.getCache().evictAll();
entityManager = entityFactory.createEntityManager();
entityManager.setProperty("javax.persistence.cache.storeMode",
CacheStoreMode.BYPASS);
entityManager.clear(); // just in case
destroyEntityManager(): end of each request
if (entityManager != null) {
if (entityManager.getTransaction().isActive()) {
entityManager.flush();
entityManager.getTransaction().commit();
}
entityManager.clear();
if (entityManager.isOpen()) {
entityManager.close();
}
entityManager = null;
}
destroy(): end of servlet
destroyEntityManager();
if (entityFactory != null) {
entityFactory.close();
}
persistence.xml:
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">
<persistence-unit name="WallMountBackOffice-PU">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>...</class>
<class>...</class>
<properties>
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" />
<property name="hibernate.connection.url" value="jdbc:mysql://localhost/ourschema" />
<property name="hibernate.connection.username" value="root" />
<property name="hibernate.connection.password" value="" />
<property name="hibernate.connection.pool_size" value="10" />
<property name="hibernate.connection.autocommit" value="false" />
<property name="hibernate.connection.release_mode" value="on_close" />
<property name="dialect" value="org.hibernate.dialect.MySQLDialect" />
<property name="hibernate.cache.use_second_level_cache"
value="false" />
<property name="hibernate.cache.use_query_cache" value="false" />
<property name="javax.persistence.sharedCache.mode" value="NONE" />
<property name="org.hibernate.cacheable" value="false" />
</properties>
</persistence-unit>
The code which does the 'select ...':
...
Query jpaQuery = entityManager.createQuery(query);
entityManager.getTransaction().begin();
jpaQuery.executeUpdate();
entityManager.getTransaction().commit();

Answer 1

In first line, there is a mistake, it must be "BYPASS" not "REFRESH", as following:
query.setHint("javax.persistence.cache.retrieveMode", "BYPASS");
And using the JPA enums instead of string literals is recommended, so it will be:
query.setHint(QueryHints.CACHE_RETRIEVE_MODE, CacheRetrieveMode.BYPASS);
query.setHint(QueryHints.CACHE_STORE_MODE, CacheStoreMode.REFRESH);

Answer 2

You can use setHint() storeMode or retrieveMode method. If you are trying to retrieve the record, use retrieveMode with BYPASS.
For Hibernate
query.setHint("javax.persistence.cache.storeMode", "REFRESH");
query.setHint("javax.persistence.cache.retrieveMode", "REFRESH");
For EclipseLink.
query.setHint("javax.persistence.cache.storeMode", "REFRESH");
query.setHint("javax.persistence.cache.retrieveMode", "REFRESH");
JPA 2.0 Specification
public enum CacheRetrieveMode {
/**
* Read entity data from the cache: this is
* the default behavior.
*/
USE,
/**
* Bypass the cache: get data directly from
* the database.
*/
BYPASS
}
public enum CacheStoreMode {
/**
* Insert/update entity data into cache when read
* from database and when committed into database:
* this is the default behavior. Does not force refresh
* of already cached items when reading from database.
*/
USE,
/**
* Don't insert into cache.
*/
BYPASS,
/**
* Insert/update entity data into cache when read
* from database and when committed into database:
* Forces refresh of cache for items read from database.
*/
REFRESH
}