Memory leak because of HibernateSessionImpl in Spring batch

Question

I've written a spring batch application that uses JPA+ Hibernate model for read-write operations.

I'm getting OutOfmemory error due to hibernateSessionImpl object.

I'm using JPA entity manager factory: org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean

as a singleton bean configured in spring.xml

Error:

java.lang.OutOfMemoryError
at java.util.HashMap.createHashedEntry(HashMap.java:650)
at java.util.HashMap.putImpl(HashMap.java:629)
at java.util.HashMap.put(HashMap.java:605)
at org.hibernate.event.def.AbstractFlushingEventListener.postFlush(AbstractFlushingEventListener.java:366)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:52)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
at org.hibernate.ejb.AbstractEntityManagerImpl.flush(AbstractEntityManagerImpl.java:960)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:600)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:240)
at $Proxy43.flush(Unknown Source)
at com.bunge.portal.core.dao.jpa.RssGenericDaoJpaImpl.create(RssGenericDaoJpaImpl.java:200)
at com.bunge.portal.rss.repository.RssFeedContentCacheRepositoryImpl.create(RssFeedContentCacheRepositoryImpl.java:17)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:600)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:318)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy44.create(Unknown Source)
at com.bunge.portal.rss.service.RssFeedServiceImpl.createRssFeedContentCache(RssFeedServiceImpl.java:46)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:600)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:318)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
15:22:08,023 ERROR AbstractStep:212 - Encountered an error executing the step
org.springframework.batch.core.JobExecutionException: Partition handler returned an unsuccessful step
at org.springframework.batch.core.partition.support.PartitionStep.doExecute(PartitionStep.java:110)
at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:195)
at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:135)
at org.springframework.batch.core.job.flow.JobFlowExecutor.executeStep(JobFlowExecutor.java:61)
at org.springframework.batch.core.job.flow.support.state.StepState.handle(StepState.java:60)
at org.springframework.batch.core.job.flow.support.SimpleFlow.resume(SimpleFlow.java:144)
at org.springframework.batch.core.job.flow.support.SimpleFlow.start(SimpleFlow.java:124)
at org.springframework.batch.core.job.flow.FlowJob.doExecute(FlowJob.java:135)
at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:281)
at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:120)
at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:48)
at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:114)
at org.springframework.batch.core.launch.support.CommandLineJobRunner.start(CommandLineJobRunner.java:349)
at org.springframework.batch.core.launch.support.CommandLineJobRunner.main(CommandLineJobRunner.java:574)

Answer 1

The problem was we were fetching 8000 records in one of the queries and using only first record. The batch was running successfully as the number of records in table were less, but as time passed the total records were too many and it was overflowing the heap memory,i changed the query to fetch only one record the latest one and it works fine....

Thanks for you help everyone..!!