负载平衡 tomcat 中的 Hibernate 自动增量？

Question

我在 3 个负载平衡的 Tomcat 中部署了使用 Hibernate 的 Web 应用程序

而且我经常遇到以下异常

org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:253)
at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:92)
at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:87)
at org.hibernate.jdbc.AbstractBatcher.prepareBatchStatement(AbstractBatcher.java:222)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2224)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2660)
at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:56)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:250)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:234)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:141)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
at com.googlecode.s2hibernate.struts2.plugin.interceptors.SessionTransactionInjectorInterceptor.intercept(SessionTransactionInjectorInterceptor.java:181)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.ajp.AjpAprProcessor.process(AjpAprProcessor.java:197)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1770)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

原因: java.sql.BatchUpdateException:键“PRIMARY”的重复条目“145985” 在 com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1666) 在 com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1082) 在 com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeBatch(NewProxyPreparedStatement.java:1723) 在 org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48) 在 org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246) ... 38 更多

我使用了以下配置

@Id
@GenericGenerator(name = "generator", strategy = "increment")
@GeneratedValue(generator = "generator")
@Basic(optional = false)
@Column(name = "address_id", nullable = false)
private Long addressId;

Answer 1

IncrementGenerator不是集群安全的，如源中所述。它通过第一次读取最大 id 值并在内存中保持递增来工作。在您的情况下，假设在开始时最大值为 10。3 个节点的 IncrementGenerator 可能将值读取为 10，并将 11 分配为在每个节点中创建的实例的 ID。

始终依靠您的数据库 ID 生成机制来实现集群安全。