I have a ScheduledLockConfiguration bean configuration.
#Bean
public ScheduledLockConfiguration taskScheduler(LockProvider lockProvider) {
return ScheduledLockConfigurationBuilder
.withLockProvider(lockProvider)
.withPoolSize(5)
.withDefaultLockAtMostFor(Duration.ofMinutes(5))
.build();
}
I just upgraded to shedlock-spring 3.0, and I don't know what to use instead of this Bean?
We can configure like below.
#Component
class TaskScheduler {
#Scheduled(cron = "0 0 10 * * ?")
#SchedulerLock(name = "TaskScheduler_scheduledTask", lockAtLeastForString = "PT5M", lockAtMostForString = "PT14M")
public void scheduledTask() {
// ...
}
}
#Scheduled will support corn format.
#SchedulerLock, the name parameter has to be unique and ClassName_methodName is typically enough to achieve that. We don't want more than one run of this method happening at the same time, and ShedLock uses the unique name to achieve that.
First, we've added lockAtLeastForString so that we can put some distance between method invocations. Using “PT5M” means that this method will hold the lock for 5 minutes, at a minimum. In other words, that means that this method can be run by ShedLock no more often than every five minutes.
Next, we added lockAtMostForString to specify how long the lock should be kept in case the executing node dies. Using “PT14M” means that it will be locked for no longer than 14 minutes.
In normal situations, ShedLock releases the lock directly after the task finishes. Now, really, we didn't have to do that because there is a default provided in #EnableSchedulerLock, but we've chosen to override that here.
Related
I have 2 instances of my Spring boot application, I am using spring JPA.
Cron scheduler run method every one hour which
first, check if record is already updated, if it's updated it should skip and don't update, but it's updated anyway on both instances.
How to implement, something like synchronized, allow to read only when something is done?
#Scheduled(cron = "0 0 * * * ?", zone = "Europe/Paris")
public void updateServers() {
applicationServerRepository.findAll().forEach(this::updateServerInfo);
}
Please explain the problem more detailed&exact.
But as I understand, you should:
Or run the cron jobs only in one instance. (Back in 90ies we did it "manually", but spring-boot-profiles offer here great opportunity: decorate "all #scheduled beans" (re-factoring!?) with #Profile("cronFooBar"), and activate/add it only on one instance.)
Or, if you also want cron jobs "load balanced", then you should find a way to synchronize/lock. (probably best in updateServerInfo or updateServers. (more details!? ..I am sure both instances will find "some object to lock on", at least the database (table, row, ..)))
As proposed by Erkan/found on internet, with "little setup" (and discarding quartz!), you can have a handy annotation for this, like:
#SchedulerLock(name = "...",
lockAtLeastForString = "...", lockAtMostForString = "...")
But I suppose, it is also possible with spring-data-jpa (only & quartz) resources, like:
Add (pessimistic) locking:
interface ApplicationServerRepository ... {
#Lock(LockModeType.PESSIMISTIC_READ)
#Query("select as from ApplicationService ...")
findAllForCron();
...
}
Catch it:
#Scheduled(cron = "0 0 * * * ?", zone = "Europe/Paris")
public void updateServers() {
try {
applicationServerRepository
.findAllForCron()
.forEach(this::updateServerInfo);
}
catch (javax.persistence.PessimisticLockException plex) {
logger.info("i get some coffee");
return;
}
}
I would Like to schedule a method using The annotation #Scheduled using cron, For example I want that the method should be executed everyday in the time specified by the client.
So I would like to get the cron value from the DB, in order to give the client the possibility of executing the method whenever he wants.
Here is my method, it sends emails automatically at 10:00 am to the given addresses, so my goal is to make the 10:00 dynamic.
Thanks for your help.
#Scheduled(cron = "0 00 10* * ?")
public void periodicNotification() {
JavaMailSenderImpl jms = (JavaMailSenderImpl) sender;
MimeMessage message = jms.createMimeMessage();
MimeMessageHelper helper;
try {
helper = new MimeMessageHelper(message, MimeMessageHelper.MULTIPART_MODE_MIXED_RELATED, StandardCharsets.UTF_8.name());
List<EmailNotification> emailNotifs = enr.findAll();
for (EmailNotification i : emailNotifs)
{
helper.setFrom("smsender4#gmail.com");
List<String> recipients = fileRepo.findWantedEmails(i.getDaysNum());
//List<String> emails = recipientsRepository.getScheduledEmails();
String[] to = recipients.stream().toArray(String[]::new);
helper.setTo(to);
helper.setText(i.getMessage());
helper.setSubject(i.getSubject());
sender.send(message);
System.out.println("Email successfully sent to: " + Arrays.toString(to));
}
}
catch (MessagingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
So I'm thinking at the next solution. ( + using the answer accepted here )
Let's say you have a class that imlpements Runnable interface -> this will be your job that gets executed. Let's call it MyJob
Also assume that we have a map that hold the id of the job and it's execution reference ( you'll see in a sec what i'm talking about). Call it something like currentExecutingJobs
Assume you have an endpoint that gets the name of the job and a cron expression from the client
When that endpoints gets called:
You'll look in the map above to see if there is any entry with that job id. If it exists, you cancel the job.
After that, you'll create an instance of that job ( You can do that by using reflection and having a custom annotation on your job classes in which you can provide an id. For example #MyJob("myCustomJobId" )
And from the link provided, you'll schedule the job using
// Schedule a task with the given cron expression
ScheduledFuture myJobScheduledFutere = executor.schedule(myJob, new CronTrigger(cronExpression));
And put the result in the above map currentExecutingJobs.put("myCustomJobId", myJobScheduledFutere)
ScheduledFuture docs
In case you want to read property from database you can implement the EnvironmentPostProcessor and read the necessary values from DB and add it to Environment object, more details available at https://docs.spring.io/spring-boot/docs/current/reference/html/howto.html#howto-spring-boot-application
I have my task to be scheduled to start after 1 min and then every 15 sec it will again run after completing my task execution. so I have my scheduler like:-
#Scheduled(initialDelay=60000, fixedDelay=15000)
public void runTask(){
// some code
}
Now I need to take initialDelay at runtime means if JVM start then I have a method "initialDelayCalculate" which calculate that, after how many hours or minute or sec my scheduler will invoke.
The time calculation method like:-
public long initialDelayCalculate(){
// time calculation
}
So it is any kind of solution to take initialDelay value from my calculation method ,like :-
#Scheduled(initialDelay={initialDelayCalculate()}, fixedDelay=15000)
public void runTask(){
// some code
}
I need a small piece of code which will solve my problem. I don't want to go for any new implementation. So please anyone can explain for any solution that how I can take value on initialDelay at runtime?
I got my solution by just calling method name as below:-
#Scheduled(initialDelayString="#{initialDelayCalculate}", fixedDelay=15000)
public void runTask(){
// some code
}
And for initialDelayCalculate method I created as bean so it will call at first when JVM up. Like:-
#Bean
public long initialDelayCalculate(){
// time calculation
}
Now it working as per my requirement. :)
We are using java 8 parallel stream to process a task, and we are submitting the task through ForkJoinPool#submit. We are not using jvm wide ForkJoinPool.commonPool, instead we are creating our own custom pool to specify the parallelism and storing it as static variable.
We have validation framework, where we subject a list of tables to a List of Validators, and we submit this job through the custom ForkJoinPool as follows:
static ForkJoinPool forkJoinPool = new ForkJoinPool(4);
List<Table> tables = tableDAO.findAll();
ModelValidator<Table, ValidationResult> validator = ValidatorFactory
.getInstance().getTableValidator();
List<ValidationResult> result = forkJoinPool.submit(
() -> tables.stream()
.parallel()
.map(validator)
.filter(result -> result.getValidationMessages().size() > 0)
.collect(Collectors.toList())).get();
The problem we are having is, in the downstream components, the individual validators which run on separate threads from our static ForkJoinPool rely on tenant_id, which is different for every request and is stored in an InheritableThreadLocal variable. Since we are creating a static ForkJoinPool, the threads pooled by the ForkJoinPool will only inherit the value of the parent thread, when it is created first time. But these pooled threads will not know the new tenant_id for the current request. So for subsequent execution these pooled threads are using old tenant_id.
I tried creating a custom ForkJoinPool and specifying ForkJoinWorkerThreadFactory in the constructor and overriding the onStart method to feed the new tenant_id. But that doesnt work, since the onStart method is called only once at creation time and not during individual execution time.
Seems like we need something like the ThreadPoolExecutor#beforeExecute which is not available in case of ForkJoinPool. So what alternative do we have if we want to pass the current thread local value to the statically pooled threads?
One workaround would be to create the ForkJoinPool for each request, rather than make it static but we wouldn't want to do it, to avoid the expensive nature of thread creation.
What alternatives do we have?
I found the following solution that works without changing any underlying code. Basically, the map method takes a functional interface which I am representing as a lambda expression. This expression adds a preExecution hook to set the new tenantId in the current ThreadLocal and cleaning it up in postExecution.
forkJoinPool.submit(tables.stream()
.parallel()
.map((item) -> {
preExecution(tenantId);
try {
return validator.apply(item);
} finally {
postExecution();
}
}
)
.filter(validationResult ->
validationResult.getValidationMessages()
.size() > 0)
.collect(Collectors.toList())).get();
The best option in my view would be to get rid of the thread local and pass it as an argument instead. I understand that this could be a massive undertaking though. Another option would be to use a wrapper.
Assuming that your validator has a validate method you could do something like:
public class WrappingModelValidator implements ModelValidator<Table. ValidationResult> {
private final ModelValidator<Table. ValidationResult> v;
private final String tenantId;
public WrappingModelValidator(ModelValidator<Table. ValidationResult> v, String tenantId) {
this.v = v;
this.tenantId = tenantId;
}
public ValidationResult validate(Table t) {
String oldValue = YourThreadLocal.get();
YourThreadLocal.set(tenantId);
try {
return v.validate(t);
} finally {
YourThreadLocal.set(oldValue);
}
}
}
Then you simply wrap your old validator and it will set the thread local on entry and restore it when done.
I am in reference to Spring Roo In Action (book from Manning). Somewhere in the book it says "Roo marks the test class as #Transactional so that the unit tests automatically roll back any change.
Here is the illustrating method:
#Test
#Transactional
public void addAndFetchCourseViaRepo() {
Course c = new Course();
c.setCourseType(CourseTypeEnum.CONTINUING_EDUCATION);
c.setName("Stand-up Comedy");
c.setDescription(
"You'll laugh, you'll cry, it will become a part of you.");
c.setMaxiumumCapacity(10);
c.persist();
c.flush();
c.clear();
Assert.assertNotNull(c.getId());
Course c2 = Course.findCourse(c.getId());
Assert.assertNotNull(c2);
Assert.assertEquals(c.getName(), c2.getName());
Assert.assertEquals(c2.getDescription(), c.getDescription());
Assert.assertEquals(
c.getMaxiumumCapacity(), c2.getMaxiumumCapacity());
Assert.assertEquals(c.getCourseType(), c2.getCourseType());
}
However, I don't understand why changes in this method would be automatically rolled back if no RuntimeException occurs...
Quote from documentation:
By default, the framework will create and roll back a transaction for each test. You simply write code that can assume the existence of a transaction. [...] In addition, if test methods delete the contents of selected tables while running within a transaction, the transaction will roll back by default, and the database will return to its state prior to execution of the test. Transactional support is provided to your test class via a PlatformTransactionManager bean defined in the test's application context.
So, in other words, SpringJUnit4ClassRunner who runs your tests always do transaction rollback after test execution.
I'm trying to find a method that allows me to do a rollback when one of the elements of a list fails for a reason within the business rules established (ie: when throw my customize exception)
Example, (the idea is not recording anything if one element in list fails)
public class ControlSaveElement {
public void saveRecords(List<MyRecord> listRecords) {
Boolean status = true;
foreach(MyRecord element: listRecords) {
// Here is business rules
if(element.getStatus() == false) {
// something
status = false;
}
element.persist();
}
if(status == false) {
// I need to do roll back from all elements persisted before
}
}
...
}
Any idea? I'm working with Roo 1.2.2..