Roberto Guardascione
Reputation: 1
Handling a specific scenario with a Test to verify that it's correctly implemented the Optimistic Lock
I'm tryng to get more into Optimistic Lock and in detail, verifyng with a test, that my implementation it's correct. The implementation it's with Java 11, SpringBoot and Maven interacting with a simple Sql DB.
The scenario i want to test it's when, from two different applications, i'm tryng to update a single attribute ( handled with the @Version of jpa ) of the same entity record simultaneously. What i did was creating a simple project and do a test where in two different threads ( launched at the same time with a countdown ) i was mocking up two calls to different methods that update that attribute; I handled this services differently cause in one i just want to inform the user that the Object it's already been updated, while in the other one i want to retry the update "n" times when i encounter that specific exception.
***For using the @Retryable i inserted in the pom this dependencies:
<dependency>
<groupId>org.springframework.retry</groupId>
<artifactId>spring-retry</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
</dependency>
and in the main this annotation : @EnableRetry***
This is the entity:
@Data
@NoArgsConstructor
@AllArgsConstructor
@Entity
@Table(name="product")
public class ProductEntity {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="product_id")
private Integer productId;
@Column(name="name")
private String name;
@Column(name="version")
@Version
private Long version;
}
This is my controller:
@RestController
@RequestMapping("/api/product")
public class ProductAPIController {
@Autowired
private IProductService productService;
@PutMapping("/new-name-one")
public ResponseEntity<ProductDTO> updateProductOrFail(
@RequestBody @Valid ProductDTO productDTO)
throws Exception {
if(productDTO.getName() == null) {
throw new ValidationException("The name has to be present");
}
try {
ProductDTO updatedProduct = productService.updateProductOrFail(ProductDTO);
return new ResponseEntity<ProductDTO>(updatedProduct, HttpStatus.OK);
} catch (ObjectOptimisticLockingFailureException | OptimisticLockException e) {
throw new OptimisticLockException("The Product has been updated by another transaction", e);
}
}
@PutMapping("/new-name-two")
public ResponseEntity<ProductDTO> updateProductOtherwiseRetry(
@RequestBody @Valid ProductDTO productDTO)
throws Exception {
if(productDTO.getName() == null) {
throw new ValidationException("The name has to be present");
}
return new ResponseEntity<ProductDTO>(productService.updateProductOtherwiseRetry(productDTO), HttpStatus.OK);
}
I will skip the service Interface and go directly to the two methods inside the service:
@Service
public class ProductService implements IProductService {
@Autowired
ProductRepository productRepository;
@Autowired
ModelMapper modelMapper;
@Override
@Transactional
public ProductDTO updateProductOrFail(ProductDTO productDTO) throws ServiceException {
ProductEntity product = productRepository.findById(productDTO.getProductId())
.orElseThrow(() -> new ServiceException("Product not found"));
product.setName(productDTO.getName());
productRepository.save(product);
return modelMapper.map(product, ProductDTO.class);
}
@Override
@Transactional
@Retryable(value = {OptimisticLockException.class,
OptimisticLockingFailureException.class,
ObjectOptimisticLockingFailureException.class},
maxAttempts = 2,
backoff = @Backoff(delay = 1000))
public ProductDTO updateProductOtherwiseRetry(ProductDTO productDTO) throws ServiceException {
ProductEntity product = productRepository.findById(productDTO.getProductId())
.orElseThrow(() -> new ServiceException("Product not found"));
product.setName(productDTO.getName());
productRepository.save(product);
//log.warn("The Product has been updated by another transaction try again...");
return modelMapper.map(product, ProductDTO.class);
}
Inside my Controller class Test this is the implementation of the method:
@Test
void havingTwoConcurrencyThread_whenUpdatingTheNameOfAProduct_ThenOptimisticLockExceptionHasToBeThrown() throws Exception {
ProductEntity product = new ProductEntity();
product.setUserStoryId(null);
product.setName("New Product");
productRepository.save(product);
CountDownLatch latch = new CountDownLatch(1);
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
ProductDTO productOneToUpdate = new ProductDTO();
productOneToUpdate.setProductId(1);
productOneToUpdate.setName("Product One");
try {
latch.await();
log.info("Thread 1 has started...");
MvcResult result = mockMvc.perform(MockMvcRequestBuilders.put(LINK + "/new-name-one")
.contentType(MediaType.APPLICATION_JSON)
.content(gson.toJson(productOneToUpdate)))
.andExpect(status().is2xxSuccessful()).andReturn();
log.info("Thread 1 has performed the call");
ProductDTO productChanged = gson.fromJson(result.getResponse().getContentAsString(), new TypeToken<ProductDTO>() {
}.getType());
assertEquals("Product One", productChanged.getName());
}catch (Exception e){
log.error("Exception in Thread 1", e);
}
}
});
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
ProductDTO productTwoToUpdate = new ProductDTO();
productTwoToUpdate.setProductId(1);
productTwoToUpdate.setName("Product Two");
try {
latch.await();
log.info("Thread 2 has started...");
mockMvc.perform(MockMvcRequestBuilders.put(LINK + "/new-name-two")
.contentType(MediaType.APPLICATION_JSON)
.content(gson.toJson(productTwoToUpdate)))
.andExpect(status().isConflict());
log.info("Thread 2 has performed the call");
} catch (Exception e) {
log.error("Exception in Thread 2", e);
assertTrue(e.getCause() instanceof ObjectOptimisticLockingFailureException ||
e.getCause() instanceof OptimisticLockException);
}
}
});
t1.start();
t2.start();
latch.countDown();
t1.join();
t2.join();
}
Maybe i didn't give you enough sample code, but i can tell you that my project has succesfully been built, and inside my TestClass i have other test ( runned as Junit ) passed succesfully. When i run this test that's the result of the console:
2024-06-13 18:19:33.669 INFO 29940 --- [ Thread-5] c.p.c.controller.ProductControllerIT : Thread 2 has started...
2024-06-13 18:19:33.669 INFO 29940 --- [ Thread-4] c.p.c.controller.ProductControllerIT : Thread 1 has started...
2024-06-13 18:19:33.887 INFO 29940 --- [ Thread-4] o.h.e.j.b.internal.AbstractBatchImpl : HHH000010: On release of batch it still contained JDBC statements
2024-06-13 18:19:33.897 ERROR 29940 --- [ Thread-4] c.p.c.c.ControllerExceptionHandler : Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; statement executed: update product set name=?, version=? where product_id=? and version=?; nested exception is org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; statement executed: update product set name=?, version=? where product_id=? and version=?
org.springframework.orm.ObjectOptimisticLockingFailureException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; statement executed: update product set name=?, version=? where product_id=? and version=?; nested exception is org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; statement executed: update product set name=?, version=? where product_id=? and version=?
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:318) ~[spring-orm-5.3.30.jar:5.3.30]
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:233) ~[spring-orm-5.3.30.jar:5.3.30]
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:566) ~[spring-orm-5.3.30.jar:5.3.30]
at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:743) ~[spring-tx-5.3.30.jar:5.3.30]
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:711) ~[spring-tx-5.3.30.jar:5.3.30]
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:654) ~[spring-tx-5.3.30.jar:5.3.30]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:407) ~[spring-tx-5.3.30.jar:5.3.30]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.30.jar:5.3.30]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.30.jar:5.3.30]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:762) ~[spring-aop-5.3.30.jar:5.3.30]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:707) ~[spring-aop-5.3.30.jar:5.3.30]
at com.example.project.service.ProductService$$EnhancerBySpringCGLIB$$******.updateProductOtherwiseRetry(<generated>) ~[classes/:na]
at com.example.project.controller.ProductAPIController.updateProductOrFail(ProductAPIController.java:80) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] [...]
Caused by: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; statement executed: update product set name=?, version=? where product_id=? and version=?
at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:67) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:54) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:47) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:3571) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:3438) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:3870) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.action.internal.EntityUpdateAction.execute(EntityUpdateAction.java:202) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:604) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.engine.spi.ActionQueue.lambda$executeActions$1(ActionQueue.java:478) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:684) ~[na:na]
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:475) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:344) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:40) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1407) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:489) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3303) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2438) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:449) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:183) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:40) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:281) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:101) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:562) ~[spring-orm-5.3.30.jar:5.3.30]
... 82 common frames omitted
Exception in thread "Thread-4" Exception in thread "Thread-5" java.lang.AssertionError: Range for response status value 500 expected:<SUCCESSFUL> but was:<SERVER_ERROR>
at org.springframework.test.util.AssertionErrors.fail(AssertionErrors.java:59)
at org.springframework.test.util.AssertionErrors.assertEquals(AssertionErrors.java:122)
at org.springframework.test.web.servlet.result.StatusResultMatchers.lambda$is2xxSuccessful$3(StatusResultMatchers.java:78)
at org.springframework.test.web.servlet.MockMvc$1.andExpect(MockMvc.java:214)
at com.example.project.controller.ProductyControllerIT$5.run(ProductControllerIT.java:476)
at java.base/java.lang.Thread.run(Thread.java:834)
java.lang.AssertionError: Status expected:<409> but was:<200>
at org.springframework.test.util.AssertionErrors.fail(AssertionErrors.java:59)
at org.springframework.test.util.AssertionErrors.assertEquals(AssertionErrors.java:122)
at org.springframework.test.web.servlet.result.StatusResultMatchers.lambda$matcher$9(StatusResultMatchers.java:627)
at org.springframework.test.web.servlet.MockMvc$1.andExpect(MockMvc.java:214)
at com.example.project.controller.ProductyControllerIT$6.run(ProductControllerIT.java:504)
at java.base/java.lang.Thread.run(Thread.java:834)
2024-06-13 18:19:33.987 INFO 29940 --- [ionShutdownHook] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2024-06-13 18:19:33.988 INFO 29940 --- [ionShutdownHook] .SchemaDropperImpl$DelayedDropActionImpl : HHH000477: Starting delayed evictData of schema as part of SessionFactory shut-down'
2024-06-13 18:19:33.997 INFO 29940 --- [ionShutdownHook] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...
2024-06-13 18:19:34.004 INFO 29940 --- [ionShutdownHook] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.
The first mock up call in the first thread it's the call to the services that has the @Retryable annotation so i expect that that's the one that has to be retryed and give me a 200, while the second one it's the one that should fail. What i read from the console is that the assertion i have in the first one failed, and give me a 500 Code, while the second one succeeded instead of giving me a Conflict Code.
I don't know if my Test it's formally correct and cover the test case where, with two concurrent transaction, i can let prevail the one i want. I also am not completely sure if that's how someone has to implement correctly the Optimistick Lock. There are a lot of things that i have to learn, but i just wanted to get my hands dirty and tryng to implement it.
Also, how can i correctly verify if this works or not?
Upvotes: 0
Views: 46
Answers (1)
Andrey B. Panfilov
Reputation: 6063
Based on the stacktrace you have provided I would say the @Retryable annotation has no effect - I expect to find RetryOperationsInterceptor class among stacktrace elements, it is not present there, please check Spring Retry with Transactional topic and comments, not just accepted answer.
As regards to test plan...
Spawning threads manually is always a poor idea, use Executors.newSingleThreadExecutor() instead. Another good idea is to somehow control the execution of at least the first competitor and check the behaviour of the second one, something like:
@Autowired
TransactionTemplate txTemplate;
@Autowired
CustomerRepository customerRepository;
private long customerId;
@BeforeEach
void tearUp() {
Customer customer = new Customer();
customerRepository.save(customer);
customerId = customer.getId();
}
void test() throws Exception {
ExecutorService executorService = Executors.newSingleThreadExecutor();
try {
Future<MvcResult> future = txTemplate.execute(status -> {
Customer customer = customerRepository.findById(customerId);
customer.setFirstName("test");
// customerRepository is a JpaRepository
// we need to call flush in order to lock entity
customerRepository.saveAndFlush(customer);
Future<MvcResult> interim = executorService.submit(() -> {
// rest controller call there;
});
// check mvc controller got stuck due to locked entity
Assertions.assertThatThrownBy(() -> interim.get(10, TimeUnit.SECONDS))
.isInstanceOf(TimeoutException.class);
return interim;
});
// check the result of future
MvcResult result = future.get();
Assertions.assertThat(result)
...
} finally {
executorService.shutdownNow();
}
}
Upvotes: 0
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