Flush the session in Grails 4.0.1

Question

In past projects which were using previous versions of Grails/Hibernate I have used in services funciton:

private void cleanGorm() {
    def session = sessionFactory.currentSession
    session.flush()
    session.clear()
}

and for example during long tasks like bulk updates I have used it e.g.:

    bigListToIterate.each {

        if (it.id > 0 && it.id % 50 == 0) {
            cleanGorm()
        }
        //CRUD action
    }

However this is not working for Grails 4.0.1; athough no exception is thrown, the changes are still not reflected in the db.

How can I get it done?

I'm using:

compile "org.grails.plugins:hibernate5"
compile "org.hibernate:hibernate-core:5.4.0.Final"

Mysql version:

SELECT version();
'5.7.21'

If I inspect database, I can see that number of Rows in the table is increasing and Data Length of the table is increasing, however when I run MySQL query select * from table I can not get any results until the whole function has ended.

injecteer · Answer 1 · 2020-01-20T09:25:30.817

1

If you need to do some sort of batch-processing with your domain object, the standard way would be to call .save( flush:true ) each n times:

bigListToIterate.eachWithIndex { something, index ->
    Book b = new Book(...)
    //CRUD action
    b.save flush:index > 0 && index % 50 == 0
}

That would flush session for you.

edited Jan 20 '20 at 09:25

answered Jan 19 '20 at 22:52

injecteer

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see update. you have to flush upon `index` instead of `id` of course – injecteer Jan 20 '20 at 09:26
I have tried it but still without luck. Unfortunatelly it's still behaving the same way: no data is persisted in db until the whole loop has finished. – Michal_Szulc Jan 20 '20 at 09:54
add someting like `prinltn Book.count()` right after session flush. For fun you can also do some `sleep 100` – injecteer Jan 20 '20 at 10:07
`prinltn Book.count()` shows correct number. however it's not reflected in db – Michal_Szulc Jan 20 '20 at 12:43
that means rather that your db-ciient is laggy – injecteer Jan 20 '20 at 12:44

Flush the session in Grails 4.0.1

1 Answers1