Should You Use Spring Boot\'s OpenSessionInView?

OpenSessionInView: A Cautionary Tale in Spring Boot

The spring.jpa.open-in-view property in Spring Boot has been a source of confusion for many developers. Let's delve into its purpose, default value, and potential consequences.

What's OpenSessionInView?

OpenSessionInView (OSIV) is a feature that keeps the EntityManagerFactory open during the entire request-response cycle. This allows Hibernate (the underlying persistence provider) to automatically initialize lazy-loaded entities, even when the transaction has been committed.

Default Value

In Spring Boot 2.0 and earlier, OSIV is enabled by default if not explicitly set. This is primarily for backward compatibility with older Hibernate versions that require OSIV to function properly.

Downfalls of OSIV

While intended to simplify object initialization, OSIV can result in significant performance issues and scalability limitations:

• Increased memory consumption: OSIV keeps the EntityManager and object graphs alive throughout the request, potentially causing memory leaks.
• Concurrent transaction conflicts: OSIV allows multiple transactions to operate on the same EntityManager, leading to potential conflicts.
• Database connection overhead: Keeping database connections open beyond their intended use time wastes resources and increases connection pooling contention.

Disable OSIV

To disable OSIV and restore proper resource management, set spring.jpa.open-in-view=false in your application.properties file.

LazyInitializationException

If you disable OSIV, you may encounter LazyInitializationException when accessing lazy-loaded entities. To resolve this, use Hibernate's @Fetch annotation or explicit eager fetching in your JPQL queries.

Conclusion

OpenSessionInView may seem like a convenient way to avoid lazy initialization exceptions, but its potential drawbacks outweigh its benefits. In modern Spring Boot applications, OSIV should be disabled to ensure optimal performance and resource utilization.

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