Please let me to know is getHibernateTemplate().flush() release data base connection after commit. If not what is the procedure to release data base connection.
I cant use hibernate transaction manager to resolve this.
calling flush be it on the HibernateTemplate or Session doesn't release anything it will only flush the pending sql statements to the database.
A connection will be releases as soon as the Session is closed, when this is depends on your setup.
Note: HibernateTemplate should be considered deprecated as of Hibernate 3.0.1 (this is when contextual sessions where introduced) and you should favor plain Session usage of the HibernateTemplate.
getHibernateTemplate().flush() will not release DB connection after commit. flush() will just synchronize your persistence context state with DB by firing update queries.
Connection will be closed when the hibernate session ends. However you can start a new transaction once the current one finishes.
Additional reference: function of getHibernateTemplate().flush()
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I'm using springboot+hikari+hibernate to build a rest API.
Some queries are really have and the database is really polluted and worst, there is a clear connection leak.
This is a legacy system which I wasn't part of design nor development but I need to do maintenance and I would like to debug where is the connection leak.
As far as I can see all transactions are annotated #Transaction... so there shouldn't be any connection "forgotten open"...
Is there any way for me to build a configuration class or annotate a method with something in order to be invoked right before any thread request a connection and right after the thread releases it? This way I could try to trace where is the leak source.
I've this settings on
spring.datasource.hikari.connection-timeout=60000
spring.datasource.hikari.maximum-pool-size=30
spring.datasource.hikari.idle-timeout=120000
spring.datasource.hikari.minimum-idle=10
spring.datasource.hikari.maxLifetime=1800000
spring.datasource.hikari.leakDetectionThreshold=60000
logging.level.com.zaxxer.hikari.HikariConfig=DEBUG
logging.level.com.zaxxer.hikari=TRACE
But this generates a very verbose log output and this system is in production so is almost impossible to track the problem.... I would like to create just a method for every connection acquire and release so I could myself write the log and find the source.
I have a JUnit 5 testcase which is annotated with #Transactional and it is calling save service (which uses JPA saveandFlush) first, and trying to retrieve the same data/entity by using find service, which is using plain JDBC for searching, but it is not able to find that entity.
When I tried using isolation of the transaction as read_uncommitted it threw exception saying "java.sql.SQLException: READ_COMMITTED and SERIALIZABLE are the only valid transaction levels" please note that I am using Oracle database.
Is there any other way we can read the data which is present in same transaction by JDBC code?
Oracle does not implement Read Uncommited isolation level, so you will not be able to see uncommited changes from other sessions.
As Mark Rotteveel and Marmite Bomber said, two different transactions/connections(JPA and JDBC) can not see each other's uncommitted data, specially for application having Oracle database.
I had to use spring managed jdbc template so that JPA and the JDBC template uses the same transaction and data is visible to each other.
Two spring boot applications are connected to the common database.
I just wanted to know, how to handle the transaction if both the application try to update the record at the same time?
Since you seem to use JPA (via Spring Data JPA) there isn't much to handle.
The database itself will prevent two transactions to update the record at the same time. So one will always be first.
If you use optimistic locking (which is the default with JPA) the second transaction will notice the modified row and rollback.
Without that the second transaction will simply overwrite the changes with it's own changes.
I am working with enterprise application that uses Spring 3.x with Hibernate annotated programming.I am working with hibernate Session object for performing db operations in my XYZDaoImpl class.
And my doubt is "Is it correct way to close Hibernate Session object every time after performing any CRUD operation?"
If it is not the correct way, please advise me the recommended way of opening/closing of hibernate Session Object.
can you post a bit daoImpl code......
If you use sessionFactory.getCurrentSession(), you will get current session..in this case framework automatically flushed and closed when the transaction ends (commit or rollback).
If you use sessionFactory.openSession(), you have to manage the session yourself and to flush and close it "manually".
No, when using hibernate with spring, you should not (manually) open or close sessions, but let spring manage the hibernate session for you. Spring manages the session as a transactional resource, so you have to configure transaction management correctly.
If you open/close the hibernate session manually, you are hardly using the integration between these two frameworks: the session management is the main feature of the integration.
The only reason to open/close a hibernate session in a spring context is to use the same session to span multiple transactions.
I have a very interesting situation. I am slightly new to JBoss and Oracle, having worked mostly with Weblogic on DB2. That said, what I am trying to do is pretty simple.
I have a local-tx-datasource to an Oracle database. From my Java I code, I invoke datasource.getConnection() after retrieving the datasource using the appropriate JNDI name. The local-tx-datasource declaration in my -ds.xml file does not have any explicit reference to autocommit behaviour.
After getting the connection, I execute a create/update query and I get back the correct update count. Subsequently, for a short duration, I am even able to retrieve this record. However, after that the database pretends it never got the record in the first place, and there is nothing at all.
My experience with connections suggests that this happens when the connection does not commit its work, and so only that connection itself will be able to see the data in its transaction. From what I read, JBoss too follows the specification that the Connection returned is an autocommit one. I even verified this from my Java code, and it states the autocommit behaviour is set to true. However, if that was the case, why are my records not getting created / updated?
Following this, I set the Connection's autocommit behaviour to false (again from Java code), and then did the commit explicitly. Since then, there has been no issue.
What could possibly be going wrong? Is my understanding of autocommit here incorrect or does JBoss have some other interpretation of it. Please note, I do not have any transactions at all. These are very simple single record insert queries.
Please note, I do not have any transactions at all.
Wrong assumption. The local-tx-datasource starts a JTA transaction in your behalf. I'm not sure how the autocommit works in this scenario, but I suppose that autocommit applies only when you are using exclusively JDBC transactions, not JTA transactions.
In JTA, if you don't commit a transaction[*], it will be rolled back after the timeout. This explains the scenario that you are experiencing. So, I'd try to either change the local-tx-datasource to no-tx-datasource or to manually commit the transaction.
Note, however, that not managing your transactions is a bad thing. Autocommit should always be avoided. There's no better party to determine when to commit than your application. Leaving this responsibility to the driver/container is, IMO, not very responsible :-)
[*] One exception is for operations inside EJBs, whose business methods are "automatically" wrapped in a JTA transaction. So, you don't need to explicitly commit the transaction.