Question

I have multiple machines running a service that is updating and reading values from a database using Hibernate.

Whenever I need to update a DB value in my service, I use an upgrade nowait lock, and if I can’t get the lock, I just retry later.

void lock(Job job) {
    sessionFactory.session.lock(job, LockMode.UPGRADE_NOWAIT);
}

There is one place in my service where I must update the DB value there, and I cannot retry. I figured I’d just use a normal upgrade lock in those spots, and it can just wait however long it needs to update the value.

void waitForLock(Job job) {
    sessionFactory.session.lock(job, LockMode.UPGRADE);
}

But now I see this error pop up sometimes…

org.hibernate.dialect.HSQLDialect - HSQLDB supports only READ_UNCOMMITTED isolation

Is there a way to guarantee that this value will be updated first time using Hibernate?

Answer 1

You are using an old version of HSQLDB which does not support transaction isolation. Use the latest version (2.2.8 or later) which does.