My Spring/Java web application has #Transactional services that can touch the database:
#Transactional
public class AbstractDBService { ... }
Desired functionality is for any uncaught throwable that propagates up beyond the service layer to cause a rollback. Was a bit surprised this isn't the default behaviour but after a bit of googling tried:
#Transactional(rollbackFor = Exception.class)
This seems to work except when an exception is deliberately swallowed and not rethrown. (The particular case is when an entity is not found. Guess this could be redesigned to not throw an Exception but expect there will inevitably be others - e.g. one that springs to mind is an InterruptedException when using Thread.sleep()). Then Spring complains:
org.springframework.transaction.TransactionSystemException: Could not commit JPA transaction; nested exception is
javax.persistence.RollbackException: Transaction marked as
rollbackOnly
...truncated..
Caused by: javax.persistence.RollbackException: Transaction marked as rollbackOnly
at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:58)
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:517)
Am I missing something here?... Is there a way to tell Spring to rollback on all uncaught throwables?
If you want to rollback on all uncaught Throwables, you can specify that in the annotation:
#Transactional(rollbackFor = Throwable.class)
By default Spring doesn't rollback for Error subclasses, probably because it seems doubtful once an Error is thrown that the JVM will be in a good enough state to do anything about it anyway, at that point the transaction can just time out. (If you try to rollback when an OutOfMemoryError is raised, the most likely outcome is another OutOfMemoryError.) So you may not gain much with this.
When you mention the case of swallowing an exception, there's no way Spring can be expected to know about it because the exception is not finding its way to Spring's proxy (which is implementing the transactional functionality). This is what happens in your RollbackException example, Hibernate has figured out the transaction needs to rollback but Spring didn't get the memo because somebody ate the exception. So Spring isn't rolling the transaction back, it thinks everything is ok and tries to commit, but the commit fails due to Hibernate having marked the transaction rollback-only.
The answer is to not swallow those exceptions but let them be thrown; making them unchecked is supposed to make it easier for you to do the right thing. There should be an exception handler set up to receive exceptions thrown from the controllers, most exceptions thrown at any level of the application can be caught there and logged.
Related
Currently we are facing a spring transaction related issue in our application.
As you can see that in deleteRecord() we are doing a DB operation. But in the next line
a business exception is thrown.
Expected Behavior(As per my knowledge) :
The DB operation should be rolled back as exception is thrown from the next line
Actual Behavior :
Its not getting rolled back. Data is getting inserted to the table
Question :
Why transaction is not getting rolled back ? I dont think its because of the catch block
because deleteRecord() will be executed in new transaction. Please correct me if I am wrong
Code:
class A {
void myMethod() {
for(int i=0 ; i<count ; i++) {
try {
deleteRecord();
} catch(Exception e) {
log.error("Exception caught");
}
}
}
#Transactional(propagation = Propagation.REQUIRES_NEW)
deleteRecord() throws Exception{
line 1 : deleting record
line 2 : Throwing business exception
}
}
The Spring documentation says the following:
While the EJB default behavior is for the EJB container to automatically roll back the transaction on a system exception (usually a runtime exception), EJB CMT does not roll back the transaction automatically on an application exception (that is, a checked exception other than java.rmi.RemoteException). While the Spring default behavior for declarative transaction management follows EJB convention (roll back is automatic only on unchecked exceptions), it is often useful to customize this.
And
In its default configuration, the Spring Framework’s transaction
infrastructure code only marks a transaction for rollback in the case
of runtime, unchecked exceptions; that is, when the thrown exception
is an instance or subclass of RuntimeException. ( Errors will also -
by default - result in a rollback). Checked exceptions that are thrown
from a transactional method do not result in rollback in the default
configuration
see in 16.5.3: https://docs.spring.io/spring/docs/4.2.x/spring-framework-reference/html/transaction.html
This says that the default behavior of the transaction will only rollback for RuntimeExceptions. If you have a own business exception (could be a checked excpetion), you have to explicitly name the exception class the transaction should rollback for:
#Transactional(propagation = Propagation.REQUIRES_NEW, rollbackFor = YOUREXCEPTION.class)
change to
#Transactional(propagation = Propagation.REQUIRES_NEW, rollbackFor = Exception.class)
It is because of #Transaction method call by the method within the same class, does not work if you do not configured Spring to use AspectJ.
Spring #Transaction method call by the method within the same class, does not work?
To rollback when have error, I use javax.ejb.SessionContext to do that,
first I mark a point to rollback by sessionContext.getUserTransaction().begin()
Then I use sessionContext.getUserTransaction().rollback() to rollback and use sessionContext.getUserTransaction().commit(); to should complete transaction before returning.
but the problem is if there is nothing changed, this will throws org.hibernate.exception.GenericJDBCException: could not prepare statement.
Conclusion: There is anyway to stop SessionContext ?
I am investigating an issue I have in my Spring Data + Hibernate app. I have found the issue in the logs but I am trying to understand why a hibernate exception org.hibernate.exception.LockAcquisitionException can throw a Spring org.springframework.dao.CannotAcquireLockException?
For exception reporting, I would like my exceptions to be consistent and to throw all Hibernate exceptions. Is this possible?
Caught unhandled exceptionorg.springframework.dao.CannotAcquireLockException: could not update: [com.database.model.MyTable#22791]; SQL [update MyTable set x=1, etc]; nested exception is
org.hibernate.exception.LockAcquisitionException: could not update:[com.database.model.MyTable#22791]# at
org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:246)# at
org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:221)# at
org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:521)# at
org.springframework.transaction.support.AbstractPlatformTr
why a hibernate exception org.hibernate.exception.LockAcquisitionException can throw a Spring org.springframework.dao.CannotAcquireLockException?
It doesn't. The hibernate exception gets caught and then a Spring exception gets thrown.
For exception reporting, I would like my exceptions to be consistent and to throw all Hibernate exceptions. Is this possible?
I'm not sure I understand why this would be more consistent than logging Spring exceptions or actually beneficial at all. All exceptions inherit from Throwable which offers access to its cause, which should be properly set for all Spring exceptions that are caused by other exceptions. So you can certainly navigate the the chain of causes to find the exception that you want to log. You might even find some of the methods in the various Spring Exceptions helpful, for example getMostSpecificCause.
Hibernate's LockAcquisitionException does not throw Spring's CannotAcquireLockException. Any Spring repository annotated with #Repository, which I believe Spring Data repositories innately are, will come with Spring exception translation. This is so your data layer does not leak out and is all wrapped by common Spring exceptions. See Spring's javadocs on PersistenceExceptionTranslator class or on exception translation.
To disable the translation maybe see this thread: How to deactivate Spring Data exception translation
I suppose the following stacktrace as java invocation:
B.method2 (annotated with a plain #Transactional)
A.method1 (annotated with a plain #Transactional)
Main.main (starting point of the call, with no current transaction)
I expect that a transaction is started when A.method1 is entered - and the transaction will be commited (or rolled back) when A.method1 is left. I also expect that the same transaction will be used within B.method2.
A RuntimeException is thrown from within B.method2. This is a Exception that is 'listed' for rollbackFor by default. The Exception is catched within A.method1, but it will pass the boundary of #Transactional when leaving B.method2.
This is my question: Will the (current) transaction be marked for rollback or not?
The default propagation mode is REQUIRED and method2 will use transaction started for method1. On exception this transaction will be marked for rollback, so nothing will be committed to the database. You may get UnexpectedRollbackException after method1.
This is not a desired behavior since code which started the transaction (owns it) should be in control of rollback/commit. I would reorganize your code to avoid such possibility.
All I know about this exception is from Spring's documentation and some forum posts with frostrated developers pasting huge stack traces, and no replies.
From Spring's documentation:
Thrown when an attempt to commit a transaction resulted in an unexpected rollback
I want to understand once and for all
Exactly what causes it?
Where did the rollback occur? in the App Server code or in the Database?
Was it caused due to a specific underlying exception (e.g. something from java.sql.*)?
Is it related to Hibernate? Is it related to Spring Transaction Manager (non JTA in my case)?
How to avoid it? is there any best practice to avoid it?
How to debug it? it seems to be hard to reproduce, any proven ways to troubleshoot it?
I found this to be answering the rest of question: https://jira.springsource.org/browse/SPR-3452
I guess we need to differentiate
between 'logical' transaction scopes
and 'physical' transactions here...
What PROPAGATION_REQUIRED creates is a
logical transaction scope for each
method that it gets applied to. Each
such logical transaction scope can
individually decide on rollback-only
status, with an outer transaction
scope being logically independent from
the inner transaction scope. Of
course, in case of standard
PROPAGATION_REQUIRED behavior, they
will be mapped to the same physical
transaction. So a rollback-only marker
set in the inner transaction scope
does affect the outer transaction's
chance to actually commit. However,
since the outer transaction scope did
not decide on a rollback itself, the
rollback (silently triggered by the
inner transaction scope) comes
unexpected at that level - which is
why an UnexpectedRollbackException
gets thrown.
PROPAGATION_REQUIRES_NEW, in contrast,
uses a completely independent
transaction for each affected
transaction scope. In that case, the
underlying physical transactions will
be different and hence can commit or
rollback independently, with an outer
transaction not affected by an inner
transaction's rollback status.
PROPAGATION_NESTED is different again
in that it uses a single physical
transaction with multiple savepoints
that it can roll back to. Such partial
rollbacks allow an inner transaction
scope to trigger a rollback for its
scope, with the outer transaction
being able to continue the physical
transaction despite some operations
having been rolled back. This is
typically mapped onto JDBC savepoints,
so will only work with JDBC resource
transactions (Spring's
DataSourceTransactionManager).
To complete the discussion:
UnexpectedRollbackException may also
be thrown without the application ever
having set a rollback-only marker
itself. Instead, the transaction
infrastructure may have decided that
the only possible outcome is a
rollback, due to constraints in the
current transaction state. This is
particularly relevant with XA
transactions.
As I suggested above, throwing an
exception at the inner transaction
scope, then catching that exception at
the outer scope and translating it
into a silent setRollbackOnly call
there should work for your scenario. A
caller of the outer transaction will
never see an exception then. Since you
only worry about such silent rollbacks
because of special requirements
imposed by a caller, I would even
argue that the correct architectural
solution is to use exceptions within
the service layer, and to translate
those exceptions into silent rollbacks
at the service facade level (right
before returning to that special
caller).
Since your problem is possibly not
only about rollback exceptions, but
rather about any exceptions thrown
from your service layer, you could
even use standard exception-driven
rollbacks all the way throughout you
service layer, and then catch and log
such exceptions once the transaction
has already completed, in some
adapting service facade that
translates your service layer's
exceptions into UI-specific error
states.
Juergen
Scroll a little more back in the log (or increase it's buffer-size) and you will see what exactly caused the exception.
If it happens not to be there, check the getMostSpecificCause() and getRootCause() methods of UnexpectedRollbackException- they might be useful.
Well I can tell you how to reproduce the UnexpectedRollbackException. I was working on my project, and I got this UnexpectedRollbackException in following situation. I am having controller, service and dao layers in my project.
What I did is in my service layer class,
class SomeServiceClass {
void outerTransaction() {
// some lines of code
innerTransaction();
//AbstractPlatformTransactionManager tries to commit but UnexpectedRollbackException is thrown, not here but in controller layer class that uses SomeServiceClass.
}
void innerTransaction() {
try {
// someDaoMethod or someDaoOperation that throws exception
} catch(Exception e) {
// when exception is caught, transaction is rolled back, outer transaction does not know about it.
// I got this point where inner transaction gets rolled back when I set HibernateTransactionManager.setFailEarlyOnGlobalRollbackOnly(true)
// FYI : use of following second dao access is wrong,
try {
// again some dao operation
} catch(Exception e1) {
throw e2;
}
}
}
}
I had this problem with Spring Framework 4 + Java 1.8 for this exception.
I solved it.
😊
I know that runtime exceptions rollbacks.
But in my case, project do not use runtime exceptions.
For example, we have code.
#Transactional
#Service
UserFacadeIml implements UserFacade
{
#Autowired
private UserService userService;
//throws UnexpectedRollbackException
//instead NotRuntimeEx
#Override
public void saveUser(User user)
throws NotRuntimeEx
{
return userService.saveUser(user);
}
}
I solved it, when add "Transactional(rollBackFor=NotRuntimeEx.class)" for facade.
It works, because Spring use proxy for facade and proxy for service.
When transactional rollback, proxy of service send context to facade.
But facade proxy does not understand, why transaction rollback.
#Transactional(rollBackFor=NotRuntimeEx.class)
#Service
UserServiceIml implements UserService
{
#Override
public void saveUser(User user)
throws NotRuntimeEx
{
throw new NotRuntimeEx(user);
}
}