How to handle Optimistic Locked item quantity update with concurrent users?

Question

I have method which updates to Item quantity.

MyEntity has @Version annoted version property as long.

There is an item list endpoint /items Also there is an item update endpoint /item/update (consider as product stock, buying an item)

So N concurrent users want's to update same item.

But there throws org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1 org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1 org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1 that exception. While updating.

And also at this time, /items endpoint couldn't return data. Or waits user to return with too much latency.(If updating users count too much at this time it also gets an exception timeout ).

So How can I handle that situation without any missing? (Can be good implementation )

Answer 1

Unfortunately, JPA/Hibernate does not play nice with batch inserts when there is contention: whenever any exception is thrown in the context of a Hibernate session, you're out of luck.

See 13.2.3. Exception handling of: https://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html/ch13.html#transactions-optimistic

Specifically:

No exception thrown by Hibernate can be treated as recoverable. Ensure that the Session will be closed by calling close() in a finally block.

In the past I have had to migrate JPA code to QueryDSL or fall back to raw SQL and JdbcTemplate (something like How to do multiple inserts in database using spring JDBC Template batch? ).