我的 Web 应用程序的数据库基础架构是这样分层的:
- 春季数据 JPA
- JPA
- 休眠
- C3P0 池
- MySQL
有些事务需要相当长的时间,有时一个大事务需要一分钟(目的是将数据缓存到数据库中):从用户到我的 Web 服务器的 HTTP 请求可能会开始此事务。然后,我的 Web 服务器可能会查询另一个远程第三方服务器以查找丢失的数据。收集完所有数据后,事务完成并将所有收集到的数据写入数据库。
在这个长时间运行的事务中,用户可能会重新加载我的网站。这导致在单独的线程中为相同的数据开始另一个事务。由于此事务的目的是缓存,因此此操作本质上是幂等的,我不介意进行两次相同的计算。但在这些情况下,我的 Web 应用程序偶尔会遇到以下错误。
20:12:46.392 container [Thread-24] WARN o.h.e.jdbc.spi.SqlExceptionHelper - SQL Error: 1062, SQLState: 23000
20:12:46.392 container [Thread-24] ERROR o.h.e.jdbc.spi.SqlExceptionHelper - Duplicate entry '146845042025054' for key 'PRIMARY'
20:12:46.602 container [Thread-24] INFO o.h.e.j.b.internal.AbstractBatchImpl - HHH000010: On release of batch it still contained JDBC statements
Exception in thread "Thread-24" org.springframework.dao.DataIntegrityViolationException: Duplicate entry '146845042025054' for key 'PRIMARY'; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: Duplicate entry '146845042025054' for key 'PRIMARY'
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:643)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:104)
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:516)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:394)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.data.jpa.repository.support.LockModeRepositoryPostProcessor$LockModePopulatingMethodIntercceptor.invoke(LockModeRepositoryPostProcessor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at com.sun.proxy.$Proxy45.save(Unknown Source)
at com.mycompany.MyJpaEntityDomainClass.setId(MyJpaEntityDomainClass.java:83)
at com.mycompany.MyCustomRepository.findMyJpaEntityDomainClassInstance(MyCustomRepository.java:72)
at sun.reflect.GeneratedMethodAccessor33.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at com.sun.proxy.$Proxy46.findMyJpaEntityDomainClassInstance(Unknown Source)
at com.mycompany.AnotherDomainEntityClass.setAssociatedJpaEntityDomainInstances(AnotherDomainEntityClass.java:343)
at com.mycompany.MyThreadInvokingService$SearcherThread.run(MyThreadInvokingService.java:106)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.hibernate.exception.ConstraintViolationException: Duplicate entry '146845042025054' for key 'PRIMARY'
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:74)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:129)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at com.sun.proxy.$Proxy76.executeUpdate(Unknown Source)
at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:56)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2962)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3403)
at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:88)
at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:362)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:354)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:275)
at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:326)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:52)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1210)
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:399)
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:175)
at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:75)
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:512)
... 31 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '146845042025054' for key 'PRIMARY'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1040)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2468)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2719)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2450)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2371)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2355)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:105)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
... 48 more
对的调用com.sun.proxy.$Proxy45.save
实际上是对 的save
方法的调用MyJpaEntityDomainClassRepository extends org.springframework.data.jpa.repository.JpaRepository<MyJpaEntityDomainClass, String>
。
正如您可以从该堆栈跟踪中推断的那样,MyJpaEntityDomainClass
实例负责在存储库中创建和更新自己。
我感觉重复条目错误发生在两个并发线程试图将相同实体写入数据库的情况下。我根本不明白为什么会发生这个错误,因为org.springframework.data.jpa.repository.JpaRepositor.save( uniqueId )
稍晚一点的线程应该只覆盖uniqueId
稍早一点的线程放入存储库的相关实体/记录。
如何避免此类与交易相关的重复进入竞争条件错误?