提高性能异步Parallel.Foreach

Question

我有一个超过10k项的deviceList，并希望通过调用另一种方法发送数据。

我尝试使用Parallel.Foreach，但我不确定这是否是正确的方法。

我已经在azure上发布了这个webapp，我已经测试了这个100它工作正常但是10k它有超时问题。我的实现是否需要任何调整，谢谢

private List<Task> taskEventList = new List<Task>();
public async Task ProcessStart()
{
    string messageData = "{\"name\":\"DemoData\",\"no\":\"111\"}";
    RegistryManager registryManager;

    Parallel.ForEach(deviceList, async (device) =>
    {
        // get details for each device and use key to send message
        device = await registryManager.GetDeviceAsync(device.DeviceId);
        SendMessages(device.DeviceId, device.Key, messageData);
    });

    if (taskEventList.Count > 0)
    {
        await Task.WhenAll(taskEventList);
    }
}

private void SendMessages(string deviceId, string Key, string messageData)
{
    DeviceClient deviceClient = DeviceClient.Create(hostName, new DeviceAuthenticationWithRegistrySymmetricKey(deviceId, deviceKey), Microsoft.Azure.Devices.Client.TransportType.Mqtt);
    //created separate Task
    var taskEvents = Task.Run(() => ProcessMessages(deviceId, string messageData));
    taskEventList.Add(taskEvents);
}

private async Task ProcessMessages(string deviceId, string messageData)
{
    var startTime = DateTime.UtcNow;
    while (DateTime.UtcNow - startTime < TimeSpan.FromMinutes(15))
    {
        await deviceClient.SendEventAsync(messageData);
    }
}

Answer 1

至少肯定存在竞争条件。 Parallel仅用于同步代码，而不是异步代码。

据我所知，你不需要Parallel或Task.Run（它们都是ASP.NET服务的反模式）：

public async Task ProcessStart()
{
  string messageData = "{\"name\":\"DemoData\",\"no\":\"111\"}";
  RegistryManager registryManager;

  var tasks = deviceList.Select(async device =>
  {
    // get details for each device and use key to send message
    device = await registryManager.GetDeviceAsync(device.DeviceId);
    await SendMessagesAsync(device.DeviceId, device.Key, messageData);
  }).ToList();

  await Task.WhenAll(tasks);
}

private async Task SendMessagesAsync(string deviceId, string Key, string messageData)
{
  DeviceClient deviceClient = DeviceClient.Create(hostName, new DeviceAuthenticationWithRegistrySymmetricKey(deviceId, deviceKey), Microsoft.Azure.Devices.Client.TransportType.Mqtt);
  await ProcessMessagesAsync(deviceId, string messageData);
}

private async Task ProcessMessagesAsync(string deviceId, string messageData)
{
  var startTime = DateTime.UtcNow;
  while (DateTime.UtcNow - startTime < TimeSpan.FromMinutes(15))
  {
    await deviceClient.SendEventAsync(messageData);
  }
}

10k它有超时问题。

HTTP请求需要15分钟。我认为退一步看看是否有更好的方法来构建整个系统是值得的。