Question

当我们的系统负载很重，几十个并发事务时，我得到乐观锁定失败错误。应用程序在与单个数据库实例通信的多个服务器上进行负载平衡。

据我所知，其核心是GORM乐观锁定机制。新线程在原始线程中加载域变量时会更改域对象属性并尝试更改。

如果是这样，处理它的最佳方法是什么？我不想处理错误，因为滚动整个事务并不是一个好的解决方案。

我有什么选择？

声明版本为false？这是否会阻止对该域对象的乐观锁定并允许并发线程更改它，即使这意味着在没有错误的情况下相互覆盖？
通过使用Object.lock（id）检索域对象的持续时间来锁定域对象？如果没有测试，很难说性能有多大，但这是最好的方法吗？
还有其他选择吗？

下面包含相关代码。如果锁定是最好的方法，那么我如何实现它，因为Object是从未保存的父对象访问子节点的？

ProductOrderService中的第390行。

private rollbackInventory(Order order) {
    order.items.each {orderItem->
        Product product = orderItem.product
        product.increaseQuantityBy(orderItem.qty)
        product.save(flush: true)
    }
}

Product domain类中的increaseQuantityBy方法如下所示：

.......

Integer qty

.......

public void increaseQuantityBy(Integer change) {
    changeQuantityBy(change)
}

public void decreaseQuantityBy(Integer change) {
    changeQuantityBy(-change)
}

private void changeQuantityBy(Integer change) {
    qty += change
}

这是错误：

2016-04-29 08:08 -- ERROR-grails.app.controllers.com.shop.order.ProductOrderController:Exception occurred. Object of class [com.shop.Product] with identifier [5774]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [com.shop.Product#5774]
org.springframework.orm.hibernate4.HibernateOptimisticLockingFailureException: Object of class [com.shop.Product] with identifier [5774]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [com.shop.Product#5774]
        at com.shop.order.ProductOrderService$_rollbackInventory_closure5.doCall(ProductOrderService.groovy:390)
        at com.shop.order.ProductOrderService.rollbackInventory(ProductOrderService.groovy:387)
        at com.shop.order.ProductOrderService.processOrder(ProductOrderService.groovy:178)
        at com.shop.order.ProductOrderController.order(ProductOrderController.groovy:240)
        at grails.plugin.cache.web.filter.PageFragmentCachingFilter.doFilter(PageFragmentCachingFilter.java:198)
        at grails.plugin.cache.web.filter.AbstractFilter.doFilter(AbstractFilter.java:63)
        at grails.plugin.springsecurity.web.filter.GrailsAnonymousAuthenticationFilter.doFilter(GrailsAnonymousAuthenticationFilter.java:53)
        at grails.plugin.springsecurity.web.authentication.RequestHolderAuthenticationFilter.doFilter(RequestHolderAuthenticationFilter.java:53)
        at grails.plugin.springsecurity.web.authentication.logout.MutableLogoutFilter.doFilter(MutableLogoutFilter.java:62)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [com.shop.Product#5774]
        ... 12 more

如何处理GORM中的乐观锁定失败

0 个答案: