如何使用Doctrine在死锁后重试事务？ [英] How to retry transaction after a deadlock using Doctrine?

问题描述

我正在编写一个PHP函数，用于将大量数据存储/更新到表中，并可能导致死锁。我试图调查如何重试与Doctrine失败的交易，但悲伤地没有找到任何信息在线。我最终写了以下代码：

I am writing a PHP function which store/updates large sets of data into a table and that may cause a deadlock. I tried investigating how to retry a failed transaction with Doctrine but sadly could not find any info online. I eventually wrote the following code

 $retry = 0;
 $done = false;
 while (!$done and $retry < 3) {
     try {

         $this->entityManager->flush();
         $done = true;

     } catch (\Exception $e) {
         sleep(1);

         $retry++;
     }
 }

 if ($retry == 3) {
     throw new Exception(
         "[Exception: MySQL Deadlock] Too many people accessing the server at the same time. Try again in few minutes"
     );
 }

我的问题：将在数据库中插入重复项？如果是的话，我如何强制Doctrine回滚事务？

My question: is there a chance this approach will insert duplicates in the database? if so, how can I force Doctrine to roll back the transactions?

推荐答案

死锁返回错误1213，客户端

A deadlock returns error 1213 which you should process on the client side

请注意，死锁和锁等待是不同的。在一个僵局中，没有失败的事务：他们都有罪。

Note that a deadlock and lock wait are different things. In a deadlock, there is no "failed" transaction: they are both guilty. There is no guarantee which one will be rolled back.

您必须使用 rollback ，您的样式代码才会插入重复的。例如您应该：

You must use rollback, your style code will insert duplicate. for example you should :

$retry = 0;

$done = false;


$this->entityManager->getConnection()->beginTransaction(); // suspend auto-commit

while (!$done and $retry < 3) {

    try {

        $this->entityManager->flush();

        $this->entityManager->getConnection()->commit(); // commit if succesfull

        $done = true;

    } catch (\Exception $e) {

        $this->entityManager->getConnection()->rollback(); // transaction marked for rollback only

        $retry++;

    }

}

。

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