聚合函数的 MongoCursorTimeoutException [英] MongoCursorTimeoutException for aggregate function

问题描述

我正在尝试使用聚合函数从 Mongo 集合中获取一些数据，但它给了我 MongoCursorTimeoutException.我试图一次只选择 50 条记录，并且该集合有超过 1700 万条记录.这是从 PHP 完成的，我的代码如下:

I am trying to fetch some data from the Mongo collection using aggregate function, but it is giving me MongoCursorTimeoutException. I am trying to select only fifty records at a time and the collection has over 17M records. This is done from PHP and my code is as follows :

$data = $my_collection->aggregate(array(
                                   array('$match'=>$filter_query),
                                   array('$group'=>array('_id'=>'$email')), 
                                   array('$skip'=>$offset),    
                                   array('$limit'=>$per_page)
                                 ));

而 $filter_query 是另一个包含时间映射的数组，就像

and the $filter_query is another array which contains the timestmap and it is like

Array
(
    [timestamp] => Array
        (
            [$gt] => 1383890400
            [$lt] => 1384495200
        )

)

我不知道为什么会发生这种情况，因为我试图只获取 50 条记录.我认为攻击是在选择所有记录后执行的，它导致了错误.除了侵略，还有什么更好的方法可以做到这一点?

I am not sure why this is happening as I am trying to fetch only 50 records. I think the agrression is performed after selecting all the records and it is causing the error. Any better method to do this other than aggression ?

我可以将超时设置为 -1，但这是否是一个不错的选择，因为驱动程序将永远等待以获得初始响应?

I can set the timeout to -1, but is it a good option as the driver will wait forever to get the initial response ?

推荐答案

要为聚合函数设置超时选项，您应该使用 MongoDB 对象实例的 command 函数.例如:

To set timeout option for aggregate function you should use command function of MongoDB object instance. For example:

$result = $database->command(
array(
    'aggregate' => $my_collection,
    'pipeline' => array(
        array('$match' => $filter_query),
        array('$group' => array('_id'=>'$email')),
                    array('$skip'=>$offset),
        array('$limit'=>$per_page)
    )
),
array( 'timeout' => $timeout )
);

更多信息请参考文档

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