Hibernate Envers AuditReader调用缓存实现方案咨询

Hey there! Let's tackle this caching issue with Hibernate Envers. I see you're already using Hazelcast as your second-level cache provider, but Envers queries are still hitting the DB—no surprise, since Envers doesn't automatically leverage the second-level cache for its audit queries or entities unless you explicitly configure it. Here's a step-by-step solution tailored to your use case:

一、 Enable Caching for Envers Audit Entities #

First off, Envers auto-generates audit entities (like EntityName_AUD for your audited entities) that don't have caching enabled by default. You need to explicitly enable this so Hazelcast can cache these audit records:

Option 1: Annotate Your Original Entities #

Add cache annotations directly to your audited entities—Envers will inherit this configuration for the corresponding audit entities:

@Entity
@Audited
@Cache(usage = CacheConcurrencyStrategy.READ_ONLY) // Perfect for creation revisions (ADD operations never change)
public class YourEntity {
    // Your entity fields and methods
}

For entities where you need to cache update revisions, use CacheConcurrencyStrategy.READ_WRITE instead.

Option 2: Global Configuration in persistence.xml #

If you prefer a global setup, add these properties to your persistence unit config:

<persistence-unit name="Vedantas.PU_NAME">
    <!-- Existing config -->
    <properties>
        <!-- Enable second-level and query cache -->
        <property name="hibernate.cache.use_second_level_cache" value="true"/>
        <property name="hibernate.cache.use_query_cache" value="true"/>
        <property name="hibernate.cache.region.factory_class" value="com.hazelcast.hibernate.HazelcastCacheRegionFactory"/>
        
        <!-- Set default cache strategy for Envers audit entities -->
        <property name="org.hibernate.envers.cache.strategy" value="read-only"/>
    </properties>
</persistence-unit>

二、 Enable Query Caching for AuditReader Queries #

Even with audit entities cached, Envers queries won't use the cache unless you mark them as cacheable. Update your AuditQuery calls to enable query caching:

Modify getCreationRevisionFor #

@Transactional(readOnly = true)
public OperationCtx getCreationRevisionFor(Class<?> aClass, long id) {
    auditReader = AuditReaderFactory.get(entityManager);
    log.info(new LogModel("getting creation revision for entity class: {}; id: {}").toString(), aClass.getName(), id);
    final Object[] array = (Object[]) auditReader.createQuery()
            .forRevisionsOfEntity(aClass, false, false)
            .add(AuditEntity.revisionType().eq(RevisionType.ADD))
            .add(AuditEntity.id().eq(id))
            .setMaxResults(1)
            .setCacheable(true) // Enable query caching
            .setCacheRegion("envers-creation-queries") // Assign a dedicated cache region
            .getSingleResult();
    return ((OperationCtx) array[1]);
}

Modify getLastRevisionFor #

@Transactional(readOnly = true)
public OperationCtx getLastRevisionFor(Class<?> aClass, long id) {
    log.info(new LogModel("getting last revision for entity class: {}; id: {}").toString(), aClass.getName(), id);
    auditReader = AuditReaderFactory.get(entityManager);
    final Object[] array = (Object[]) auditReader.createQuery()
            .forRevisionsOfEntity(aClass, false, false)
            .add(AuditEntity.id().eq(id))
            .add(AuditEntity.revisionNumber().maximize()
                    .computeAggregationInInstanceContext()
            )
            .addOrder(AuditEntity.revisionNumber().desc())
            .setMaxResults(1)
            .setCacheable(true) // Enable query caching
            .setCacheRegion("envers-last-revision-queries") // Dedicated cache region
            .getSingleResult();
    OperationCtx lastchg = (OperationCtx) array[1];
    OperationCtx creation = getCreationRevisionFor(aClass, id);
    if (creation.getId() == lastchg.getId()) return new OperationCtx();
    return lastchg;
}

三、 Add Declarative Business-Level Caching (Recommended) #

Since creation revisions never change and last revisions only change when the entity is updated, using Spring Cache (with Hazelcast as the backend) gives you full control over cache lifecycle:

1. Configure Spring Cache with Hazelcast #

• Add @EnableCaching to your Spring configuration class
• Set up HazelcastCacheManager (since you're already using Hazelcast for Hibernate, this integration is straightforward)

2. Cache Creation Revisions #

Annotate getCreationRevisionFor to cache its results permanently (since creation data never changes):

@Transactional(readOnly = true)
@Cacheable(value = "creationRevisions", key = "#aClass.name + ':' + #id")
public OperationCtx getCreationRevisionFor(Class<?> aClass, long id) {
    // Existing implementation
}

3. Cache Last Revisions + Evict on Entity Update #

Annotate getLastRevisionFor to cache results, then add an eviction annotation to your entity update methods to clear stale cache entries:

@Transactional(readOnly = true)
@Cacheable(value = "lastRevisions", key = "#aClass.name + ':' + #id")
public OperationCtx getLastRevisionFor(Class<?> aClass, long id) {
    // Existing implementation
}

// Example entity update method in your service
@Transactional
@CacheEvict(value = "lastRevisions", key = "#entity.getClass().name + ':' + #entity.id")
public void updateEntity(YourEntity entity) {
    entityManager.merge(entity);
}

4. Automatically Benefit in setManipulationCtx #

Your setManipulationCtx method calls the two cached methods, so it will automatically use cached data on subsequent calls—no changes needed here!

四、 Key Notes #

• Ensure Hazelcast's cache region configurations align with your needs: creation revisions can have a permanent TTL, while last revisions can either use a reasonable TTL or rely solely on @CacheEvict.
• Double-check that hibernate.cache.use_query_cache=true is set, otherwise setCacheable(true) on AuditQueries won't work.
• If using Spring Boot, Hazelcast integration is even simpler—just add the dependency and configure cache properties in application.properties.

内容的提问来源于stack exchange，提问作者greengold