I'm performing the following logic on a single Service in grails 2.4.4.
class SampleService {
void process(params1, params2) {
SampleDomain1 sd1 = new SampleDomain1()
sd1.setProperties(params1)
sd1.save()
SampleDomain2 sd2 = new SampleDomain2()
sd2.setProperties(params2)
sd2.save()
}
}
What I understand is that Services are by default transactional. If sd1.save() is successful but sd2.save() is not, it will rollback the changes and will throw an error. While if both are successful, both are committed upon service's exit.
If my understanding is correct, then both of it should already been persisted to the database. However, the problem is: it does not— unless if you explicitly use the flush: true parameter based on my tests using the same set of params1 and params2.
sd1.save(flush: true)
SampleDomain2 sd2 = new SampleDomain2()
sd2.setProperties(params2)
sd2.save(flush: true)
}
Which, by the way is what I am really avoiding (what would be the point setting it as #Transactional). If that's the catch of Hibernate 4 / Grails 2.4, what do I need to do to make my services to commit at every end of a service call again? Do I need to configure any global configuration of Grails? I really need to flush my Domain classes at the end of every service automatically.
Note
I've already assured that the data is correct, including calling .validate() and other checker. Success in performing .save(flush: true) proves that. The problem I found is regarding to the update on Grails 2.4 on its FlushMode. Now, maybe what I really need is a global settings to override this.
If your data is not being flushed to the database layer there are some possibilities that come to mind.
There's some kind of error when trying to save to the database, you can try passing failOnError=true parameter to the .save() calls to see it clearly. (Actually setting this globally is a good idea since silently failing db calls are a migraine)
You are calling this service method from within the same service object. This will not allow the underlying spring declarative transactions to work due to the use of proxies.
You might have annotated some other method in the same service, in which case the default transactional support is no longer available for the remaining un-annotated (is this even a word?) methods.
You might have created the Service somewhere outside of service folder, not quite sure if this can cause an issue since I've never tried it out.
You have failed to sacrifice a goat to the Groovy and Grails Gods and they are messing with your head.
Edit :
I'm going to try to answer the points in your new edit.
Have you tried failOnError? It might be a issue that occurs when both objects are flushed to the DB at once, instead of manually committing them one at a time.
By figuring out a way to auto flush on save, you are going to be bypassing the transactions altogether AFAIK, now if I'm wrong then by all means go for it. But do test it out first before assuming.
Somewhere on my DataSource.groovy configuration, there is this line:
hibernate {
...
singleSession = true // configure OSIV singleSession mode
flush.mode = 'manual' // OSIV session flush mode outside of transactional context
^^^^^^^^^^
}
Which explicit states that every save should be flushed manually. As a solution, I comment out this line. After that, every database transaction now commits every time it exists a Service.
Related
private void doSomething(someProcessModel process){
CustomerModel customer = process.getCustomerModel();
customer.getFoos().stream()
.filter(foo -> foo.getCountryCode().equals(process.getCountryCode()))
.findFirst()
.ifPresent(foo -> {
if(foo.getSomeNumber() == null){
foo.setSomeNumber("1234567");
modelService.save(foo);
}
});
}
As seen in the code snippet above, I have a 'CustomerModel' that has an attribute 'Foos'. It's a one-to-many relationship. As you can see I have done some filtering and in the end, I want to update the value of 'someNumber' attribute of 'Foo' if it is null. I've confirmed that everything is working as the "someNumber" attribute's value is updated during the debugging. It doesn't save at all as I have done my checking in the HMC. I have also validated that the Interceptor doesn't have any condition that would throw an error. There is nothing being shown in the log either.
I am wondering is it a legal approach to do the "modelService.save()' inside the 'ifPresent()' method? What could be the possible issue here?
I have found the root cause now as I have face the same issue again.
Context to my original question
To give more context to my original question, the #doSomething method resides in a Hybris Business Process action class and I have ended the action prematurely while I am debugging it (by stopping the debugging) once the #doSomething method is ran.
Root cause
The mentioned problem happened when I was debugging the action class. I assumed that the ModelService#save will persist the current state of the business process once it has been ran. However, the Hybris OOTB business process will do a rollback if there is any error (and I believe it was caused by me stopping the debugging half-way).
SAP Commerce Documentation:
All actions are performed inside their own transaction. This means that changes made inside the action bean run method are rolled back in case of an error.
Solution
Let the action runs completely!
Good to know
Based on the SAP Documentation and this blog post, there will be times that we will need to bypass a business process rollback even though there is an exception being thrown and there are ways to achieve that. More info can be found in this SAP Commerce Documentation and the mentioned blog post.
However, in some circumstances it may be required to let a business exception reach the outside but also commit the transaction and deal with the exception outside. Therefore, it is possible to make the task engine not roll back the changes made during a task which failed.
You have to be cautious with a list in models as they are immutable, you have to set the whole new list. Also you called save only on a particular model, which changes its Jalo reference, that's why your list is not updated. Mutating stream and collecting it in the end will create new list that's why you can stream over the list directly from the model.
private void doSomething(someProcessModel process){
CustomerModel customer = process.getCustomerModel();
ArrayList<FooModel> foos = doSomethingOnFoos(customer.getFoos());
customer.setFoos(foos);
modelService.saveAll(foos, customer);
}
//compare the value you know exists with something that might be NULL as equals can handle that, but not the other way around
private ArrayList<FooModel> doSomethingOnFoos(ArrayList<FooModel> fooList) {
return fooList.stream()
.filter(Objects::nonNull)
.filter(foo -> process.getCountryCode().equals(foo.getCountryCode()))
.filter(foo -> Objects.isNull(foo.getSomeNumber()))
.map(foo -> foo.setSomeNumber(1234))
.collect(toList());
}
RaceRegistration domain has embedded raceParticipant and raceParticipant has a field bibNumber which is Integer.
I have a method for nulling out all bibNumbers of registrations but without flush:true in save, the nulling out of bibs dont work. The bibs are not set to null.
def nullifyBibNumbers(Long id){
...
def regss = RaceRegistration.createCriteria().list(){
eq('compositeEvent', event)
}
regss.each{ r ->
r.raceParticipant.bibNumber = null
r.save()
}
render "Bibs resetted!"
}
If i add flush:true then the bibs are set to null.
regss.each{ r ->
r.raceParticipant.bibNumber = null
r.save(flush: true)
}
I am wondering why you need flush in order for the value to be set to null? I am guessing the problem is with regard to how i am obtain the registration list using createCriteria(). I appreciate any help in this dilemma i am facing. Thanks!
As you probably figured out, save(flush: true) forces Hibernate to write any pending changes to the database. Without the explicit flush, you're relying on a Hibernate transaction to automatically flush when the transaction commits.
The reason only an explicit flush is working for you is because you're not calling save() within a transaction.
The cleanest fix is to create a Grails service, put nullifyBibNumbers() in it, and make the service transactional. That will cause nullifyBibNumbers() to get wrapped in a transaction so that you can use save() without an explicit flush.
If nullifyBibNumbers() is already in a service, you can add #Transactional to the service class, just keep in mind that it will make all methods (perhaps only the public ones?) transactional. Having said that, you can use #NotTransactional on a method to disable transactions.
The value is null in your domain object. But you are talking about null in the database, I guess?
It shouldn't matter. This is basic ORM. As a developer you don't care about when the flush is done. Typically this would be at the end of a transaction. The ORM will then flush all of the changes for that transaction at once.
It works on what is called the first-level cache during the transaction, and tries to avoid going to the db until it is explicitly requested (flush:true) or required (end of transaction).
Without the using of
save(flush: true)
The object will not be persisted immediately.
You can follow the documentation link and see the following information:
The save method informs the persistence context that an instance
should be saved or updated. The object will not be persisted
immediately unless the flush argument is used.
Related to the null issue you are facing make sure that the following condition are met.
The save method returns null if validation failed and the instance was
not persisted, or the instance itself if successful.
You do not need the flush in order for the value to be set to null.
The flush only care of a quick update of the database.
ok i fixed this problem using HQL instead of domain saves. Still i would appreciate why save() didnt work and save(flush:true) saved the data. Thanks!
RaceRegistration.executeUpdate("update RaceRegistration set raceParticipant.bibNumber = null where compositeEvent.id = :ev", [ev: id])
I have the following test (which is probably more of a functional test than integration but...):
#Integration(applicationClass = Application)
#Rollback
class ConventionControllerIntegrationSpec extends Specification {
RestBuilder rest = new RestBuilder()
String url
def setup() {
url = "http://localhost:${serverPort}/api/admin/organizations/${Organization.first().id}/conventions"
}
def cleanup() {
}
void "test update convention"() {
given:
Convention convention = Convention.first()
when:
RestResponse response = rest.put("${url}/${convention.id}") {
contentType "application/json"
json {
name = "New Name"
}
}
then:
response.status == HttpStatus.OK.value()
Convention.findByName("New Name").id == convention.id
Convention.findByName("New Name").name == "New Name"
}
}
The data is being loaded via BootStrap (which admittadly might be the issue) but the problem is when I'm in the then block; it finds the Convention by the new name and the id matches, but when testing the name field, it is failing because it still has the old name.
While reading the documentation on testing I think the problem lies in what session the data gets created in. Since the #Rollback has a session that is separate from BootStrap, the data isn't really gelling. For example, if I load the data via the test's given block, then that data doesn't exist when my controller is called by the RestBuilder.
It is entirely possible that I shouldn't be doing this kind of test this way, so suggestions are appreciated.
This is definitely a functional test - you're making HTTP requests against your server, not making method calls and then making assertions about the effects of those calls.
You can't get automatic rollbacks with functional tests because the calls are made in one thread and they're handled in another, whether the test runs in the same JVM as the server or not. The code in BootStrap runs once before all of the tests run and gets committed (either because you made the changes in a transaction or via autocommit), and then the 'client' test code runs in its own new Hibernate session and in a transaction that the testing infrastructure starts (and will roll back at the end of the test method), and the server-side code runs in its own Hibernate session (because of OSIV) and depending on whether your controller(s) and service(s) are transactional or not, may run in a different transaction, or may just autocommit.
One thing that is probably not a factor here but should always be considered with Hibernate persistence tests is session caching. The Hibernate session is the first-level cache, and a dynamic finder like findByName will probably trigger a flush, which you want, but should be explicit about in tests. But it won't clear any cached elements and you run the risk of false positives with code like this because you might not actually be loading a new instance - Hibernate might be returning a cached instance. It definitely will when calling get(). I always add a flushAndClear() method to integration and functional base classes and I'd put a call to that after the put call in the when block to be sure everything is flushed from Hibernate to the database (not committed, just flushed) and clear the session to force real reloading. Just pick a random domain class and use withSession, e.g.
protected void flushAndClear() {
Foo.withSession { session ->
session.flush()
session.clear()
}
}
Since the put happens in one thread/session/tx and the finders run in their own, this shouldn't have an effect but should be the pattern used in general.
I'm using Grails 2.5.1, and I have a controller calling a service method which occasionally results in a StaleObjectStateException. The code in the service method has a try catch around the obj.save() call which just ignores the exception. However, whenever one of these conflicts occurs there's still an error printed in the log, and an error is returned to the client.
My GameController code:
def finish(String gameId) {
def model = [:]
Game game = gameService.findById(gameId)
// some other work
// this line is where the exception points to - NOT a line in GameService:
model.game = GameSummaryView.fromGame(gameService.scoreGame(game))
withFormat {
json {
render(model as JSON)
}
}
}
My GameService code:
Game scoreGame(Game game) {
game.rounds.each { Round round ->
// some other work
try {
scoreRound(round)
if (round.save()) {
updated = true
}
} catch (StaleObjectStateException ignore) {
// ignore and retry
}
}
}
The stack-trace says the exception generates from my GameController.finish method, it doesn't point to any code within my GameService.scoreGame method. This implies to me that Grails checks for staleness when a transaction is started, NOT when an object save/update is attempted?
I've come across this exception many times, and generally I fix it by not traversing the Object graph.
For example, in this case, I'd remove the game.rounds reference and replace it with:
def rounds = Round.findAllByGameId(game.id)
rounds.each {
// ....
}
But that would mean that staleness isn't checked when the transaction is created, and it isn't always practical and in my opinion kind of defeats the purpose of Grails lazy collections. If I wanted to manage all the associations myself I would.
I've read the documentation regarding Pessimistic and Optimistic Locking, but my code follows the examples there.
I'd like to understand more about how/when Grails (GORM) checks for staleness and where to handle it?
You don't show or discuss any transaction configuration, but that's probably what's causing the confusion. Based on what you're seeing, I'm guessing that you have #Transactional annotations in your controller. I say that because if that's the case, a transaction starts there, and (assuming your service is transactional) the service method joins the current transaction.
In the service you call save() but you don't flush the session. That's better for performance, especially if there were another part of the workflow where you make other changes - you wouldn't want to push two or more sets of updates to each object when you can push all the changes at once. Since you don't flush, and since the transaction doesn't commit at the end of the method as it would if the controller hadn't started the transaction, the updates are only pushed when the controller method finishes and the transaction commits.
You'd be better off moving all of your transactional (and business) logic to the service and remove every trace of transactions from your controllers. Avoid "fixing" this by eagerly flushing unless you're willing to take the performance hit.
As for the staleness check - it's fairly simple. When Hibernate generates the SQL to make the changes, it's of the form UPDATE tablename SET col1=?, col2=?, ..., colN=? where id=? and version=?. The id will obviously match, but if the version has incremented, then the version part of the where clause won't match and the JDBC update count will be 0, not 1, and this is interpreted to mean that someone else made a change between your reading and updating the data.
In my app, I have a code like this:
// 1
Foo.get(123).example = "my example" // as expected, don't change value in db
// 2
Foo.get(123).bars.each { bar ->
bar.value *= -1 // it's changing "value" field in database!! WHY?
}
note: Foo and Bar are tables in my DB
Why is gorm saving in database is second case?
I don't have any save() method in code.
Tks
SOLVED:
I need to use read() to get a readonly session.
(Foo.discard() also works)
Doc: http://grails.org/doc/latest/guide/5.%20Object%20Relational%20Mapping%20%28GORM%29.html#5.1.1%20Basic%20CRUD
(In the first case, I guess I made mistest)
Both should save, so the first example appears to be a bug. Grails requests run in the context of an OpenSessionInView interceptor. This opens a Hibernate session at the beginning of each request and binds it to the thread, and flushes and closes it at the end of the request. This helps a lot with lazy loading, but can have unexpected consequences like you're seeing.
Although you're not explicitly saving, the logic in the Hibernate flush involves finding all attached instances that have been modified and pushing the updates to the database. This is a performance optimization since if each change had been pushed it would slow things down. So everything that can wait until a flush is queued up.
So the only time you need to explicitly save is for new instances, and when you want to check validation errors.