将交易范围添加到Parallel.Foreach [英] Adding Transaction Scope to Parallel.Foreach

问题描述

我有一个循环将记录插入数据库(Firebird):

I have a loop inserting records into a database (Firebird):

using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, options))
{
    taskList.Add(Task.Factory.StartNew(() =>
    {       
        Parallel.ForEach(objectList, c =>
        {
            DoInsert(c, id);
        });
    }));

    scope.Complete()
}

如果插入失败，我希望能够将这些插入作为一批回滚.但是，当我在Parallel.Foreach循环中执行插入操作时，事务范围不可见.我假设这是因为循环在不同的线程中运行.如果我使用TransactionScope作为串行插入来执行此操作，则一切正常.

I would like the ability to rollback these inserts as a batch if the insert fails. However as I'm performing the insert within a Parallel.Foreach loop, the transaction scope isn't visible. I'm assuming that's because the loop is operating in a different thread. If I do this as a serial insert using TransactionScope, everything works.

我尝试使用DependentTransaction，但似乎无法获得DoInsert函数的上下文. DoInsert只需打开一个连接并将C的内容写入数据库.

I've tried to use a DependentTransaction but I can't seem to get the context to the DoInsert function. The DoInsert simply opens a connection and writes the contents of C to the database.

有什么想法吗?

谢谢

推荐答案

由于提到的原因，您不能使用单个TransactionScope来执行此操作:TransactionScope依赖于线程本地存储，并且您处于多线程环境中.

You cannot do this using a single TransactionScope, for the reason you mentioned: TransactionScope relies on threadlocal storage, and you are in a multithreaded environment.

但更重要的是，要使其正常工作，每个工作线程都需要打开一个连接，将其加入分布式事务中，进行插入，然后关闭连接.

But more importantly, for this to work, every worker thread would need to open a connection, enlist it in a distributed transaction, do the insert, and close the connection.

如果这是简单的插入，那么创建所有这些连接将给您带来任何性能优势，我会感到非常惊讶.实际上，我相信如果您在单个线程和单个连接上执行此程序，它将更快.显然，这意味着该连接被打开(和关闭)一次，并作为参数传递给DoInsert方法.

If this are simple inserts, I'd be very surprised that creating all these connections would give you any performance benefit. In fact, I believe this program would be a lot faster if you did it on a single thread, and on a single connection. Obviously, that implies that the connection is opened (and closed) once, and passed into the DoInsert method as a parameter.

更好的是，您可能希望查看批量插入.

Even better, you might want to look at bulk insert.

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