从存储到SQL的Azure数据工厂复制活动：挂起70000行

我有一个带有管道复制活动的数据工厂，如下所示：

{
  "type": "Copy",
  "name": "Copy from storage to SQL",
  "inputs": [
    {
      "name": "storageDatasetName"
    }
  ],
  "outputs": [
    {
      "name": "sqlOutputDatasetName"
    }
  ],
  "typeProperties": {
    "source": {
      "type": "BlobSource"
    },
    "sink": {
      "type": "SqlSink"
    }
  },
  "policy": {
    "concurrency": 1,
    "retry": 3
  },
  "scheduler": {
    "frequency": "Month",
    "interval": 1
  }
}

输入数据的大小约为90MB，约150万行，分为大约2个字节。Azure存储中的20 x 4.5MB块Blob文件。这是数据（CSV）的示例：

A81001,1,1,1,2,600,3.0,0.47236654,141.70996,0.70854986 A81001,4,11,0,25,588,243.0,5.904582,138.87576,57.392536 A81001,7,4,1,32,1342,278.0,7.5578647,316.95795， 65.65895

该接收器是类型为S2的Azure SQL Server，其额定值为50 DTU。我创建了一个简单的表，其中包含明智的数据类型，并且没有键，索引或任何花哨的东西，只有列：

CREATE TABLE [dbo].[Prescriptions](
    [Practice] [char](6) NOT NULL,
    [BnfChapter] [tinyint] NOT NULL,
    [BnfSection] [tinyint] NOT NULL,
    [BnfParagraph] [tinyint] NOT NULL,
    [TotalItems] [int] NOT NULL,
    [TotalQty] [int] NOT NULL,
    [TotalActCost] [float] NOT NULL,
    [TotalItemsPerThousand] [float] NOT NULL,
    [TotalQtyPerThousand] [float] NOT NULL,
    [TotalActCostPerThousand] [float] NOT NULL
)

源，接收器和数据工厂都在同一地区（北欧）。

根据Microsoft的“复制活动性能和调优指南”，对于Azure存储源和Azure SQL S2接收器，我应该获得0.4 MBps的速度。根据我的计算，这意味着90MB应该在大约半小时内传输（是吗？）。

由于某种原因，它非常快地复制了70,000行，然后似乎挂起了。使用SQL Management Studio，我可以看到数据库表中的行数恰好是70,000，并且在7个小时内根本没有增加。但是复制任务仍在运行，没有错误：

Any ideas why this is hanging at 70,000 rows? I can't see anything unusual about the 70,001st data row which would cause a problem. I've tried compeltely trashing the data factory and starting again, and I always get the same behaviour. i have another copy activity with a smaller table (8000 rows), which completes in 1 minute.