How to make transactional 2 writers - one JDBC writer and a flat file writer?
When for example the directory to write in doesn't exist I have a fileNotFoundException. But the other JDBC writer already wrote in database.
I tried #Transactional in the writer, but the exception occurred in the compressor.
You need to use a CompositeItemWriter with two item writers. The transaction will be around the composite writer, so if one of the delegates fails the transaction will be rolled back and the other delegate's operation will be reverted as well.
In your case, a failure in writing the file will make the database insertion to be reverted due to the rollback of the transaction.
Related
I have applied #Transactional in my interface, and inside my serviceImpl, the corresponding method is calling some other methods, one method is reading, another method is writing. Although I have anotated as Transactional, when I am giving concurrent request, my insert method is throwing org.hibernate.exception.LockAcquisitionException: error.
Another problem is, this insert method is a shared method and it performs the insert method like Dao.save(obj) . Dao.save() is a generic method So i can not do anything here. I have to apply something on interface to avoid no lock aquired exception.
Is it possible to tell wait untill lock is aquired? Or retry if transaction is failed? Or lock all the tables until the transaction is completed so that another request can not access the relevent resources?
My hibernate version is 3.x, And database is mysql 5.6
The best way to do this is,
Mark your methods transactional
In your mysql database settings set the transaction isolation level as SERIALIZABLE
Question:
Is there a way to allow Spring declarative transaction to postpone the rollback on exception ?
Use case:
I have to process several entities together in a single transaction.
The result of processing a single entity are a few new records in the DB and a few updates to existing ones.
If processing of any of those entities results in an exception, the transaction needs to be rolled back. So, all entities must be processed successfully in order for transaction to be committed.
The twist: I want to detect all the entities for which processing ends up with exception in one go. I do not want to run processing once, fail on entity No5, fix the issues on entity No5, and then run processing again only to be greeted by an exception on entity No7.
So, what I am trying to achieve is to gather all the errors on entities that are in a faulty state and notify someone to fix them. Due to this, I want the transaction that encapsulates all entities processing to carry on till the last entity and only then I want a rollback to happen.
What I tried so far:
Using propagation = NESTED like this:
#Transactional
void processAllEntities() {
entities = fetchEntities();
for (entity : entities) {
processSingleEntity();
}
}
#Transactional(propagation = NESTED)
void processSingleEntity(entity) {
do stuff;
}
Please note that methods above are in different #Component annotated classes and processAllEntities() is invoked from a third class.
This failed because JpaDialect does not support savepoints.
I tried to switch to DataSourceTransactionManager as suggested in the javadoc of Propagation.NESTED but then nothing is persisted since this transaction manager seems to be JPA unaware and my whole model is mapped with JPA annotations and I'm using spring-data-jpa for persistence.
Any ideas and feedback are welcome. Thanks.
I want to persist some data after an exception occurs in ItemWriter step. But if I am not incorrect, in this case a rollback would happen and so this persisting logic won't work.Is there any way to achieve this?
Right now, I am implementing itemWriteListener and all the persisting logic is written inside onWriteError method. This logic only concerns to change state of some entities to error.
You'll want to use a separate connection that does not participate in the transaction. For example, inject a DataSource into your listener and construct your own JdbcTemplate with an independent connection. By doing that, the writes should not be rolled back.
If you mark the onWriteError method with
#Transactional(propagation = Propagation.REQUIRES_NEW)
...would this work as well?
I have a program that uses handler, businessObject and DAO for program execution. Control starts from handler to businessObject and finally to DAO for Database operations.
For example my program does 3 operations: insertEmployee(), updateEmployee() and deleteEmployee() every method being called one after the other from handler. once insertEmployee() called control get back to handler then it calls updateEmployee() again control back to handler then it calls deleteEmployee().
Problem Statement: If my first two methods in dao are successful and control is back to handler and next method it request to dao is deleteEmployee(). Meanwhile it faces some kind of exception in deleteEmployee(). It should be able to rollback the earlier insertEmployee() and updateEmployee() operation also. It should not rollback only deleteEmployee(). It should behave as this program never ran in system.
Can any one point me how to achieve this in spring jdbcTemplate Transaction management.
You should check about transaction propagation, in special: PROPAGATION_REQUIRED.
More info:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/transaction.html#tx-propagation
Just a little background , I'm a new developer who has recently taken over a major project after the senior developer left the company before I could develop a full understanding of how he structured this. I'll try to explain my issue the best I can.
This application creates several MessageListner threads to read objects from JMS queues. Once the object is received the data is manipulated based on some business logic and then mapped to a persistence object to be saved to an oracle database using a hibernate EntityManager.
Up until a few weeks ago there hasn't been any major issues with this configuration in the last year or so since I joined the project. But for one of the queues (the issue is isolated to this particular queue), the spring managed bean that processes the received object hangs at the method below. My debugging has led me to conclude that it has completed everything within the method but hangs upon completion. After weeks of trying to resolve this I'm at end of my rope with this issue. Any help with this would be greatly appreciated.
Since each MessageListner gets its own processor, this hanging method only affects the incoming data on one queue.
#Transactional(propagation = Propagation.REQUIRES_NEW , timeout = 180)
public void update(UserRelatedData userData, User user,Company company,...)
{
...
....
//business logic performed on user object
....
......
entityMgr.persist(user);
//business logic performed on userData object
...
....
entityMgr.persist(userData);
...
....
entityMgr.flush();
}
I inserted debug statements just to walk through the method and it completes everything including entityMgr.flush.().
REQUIRES_NEW may hang in test context because the transaction manager used in unit testing doesn't support nested transactions...
From the Javadoc of JpaTransactionManager:
* <p>This transaction manager supports nested transactions via JDBC 3.0 Savepoints.
* The {#link #setNestedTransactionAllowed "nestedTransactionAllowed"} flag defaults
* to {#code false} though, since nested transactions will just apply to the JDBC
* Connection, not to the JPA EntityManager and its cached entity objects and related
* context. You can manually set the flag to {#code true} if you want to use nested
* transactions for JDBC access code which participates in JPA transactions (provided
* that your JDBC driver supports Savepoints). <i>Note that JPA itself does not support
* nested transactions! Hence, do not expect JPA access code to semantically
* participate in a nested transaction.</i>
So clearly if you don't call (#Java config) or set the equivalent flag in your XML config:
txManager.setNestedTransactionAllowed(true);
or if your driver doesn't support Savepoints, it's "normal" to get problem with REQUIRES_NEW...
(Some may prefer an exception "nested transactions not supported")
This kind of problems can show up when underlying database has locks from uncommitted changes.
What I would suspect is some other code made inserts/deletes on userData table(s) outside transaction or in a transaction which takes very long time to execute since it's a batch job or similar. You should analyze all the code referring to these tables and look for missing #Transactional.
Beside this answer, you may also check for the isolation level of your transaction — perhaps it's too restrictive.
Does the update() method hang forever, or does it throw an exception when the timeout elapses?
Unfortunately I have the same problem with Propagation.REQUIRES_NEW. Removing it resolves the problem. The debugger shows me that the commit method is hanging (invoked from #Transactional aspect implementation).
The problem appears only in the test spring context, when the application is deployed to the application server it works fine.