Events lost before reaching the segment servers

[mabead]

When using Analytics.NET version 3.4.2-beta, I found out thta a few analytics events per hour are not successfully sent to the segment servers. To troubleshoot this, I configured the Segment.Client.Failed callback:

private void LogFailure(SegmentSdk.Model.BaseAction action, Exception e)
{
    _logger.LogError(e, $"Failed to send analytic event {action.Type} for user {action.UserId} to segment.io server");
}

myClient.Failed += LogFailure;

With this in-place, I now see this error log pop-up a few times per hour. Here's what the error looks like this (The response ended prematurely):

Failed to send analytic event track for user c08cb1fb-f963-4238-b075-570f08a88892 to segment.io server
System.Net.Http.HttpRequestException: An error occurred while sending the request.
 ---> System.IO.IOException: The response ended prematurely.
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithNtConnectionAuthAsync(HttpConnection connection, HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.FinishSendAsyncBuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
   at Segment.Request.BlockingRequestHandler.MakeRequest(Batch batch)

From what I can see, the events are then completely lost. The consequence of this are pretty bad for us:

• we do an Identify to set a few traits on the user.
• these traits are then used by the customer.io destination to send some promotional messages and communications
• since some events are lost, it means that customer.io sends the wrong communications to a few of our users

Chameleon is also used to create some on-boarding flows. Since the traits are not always sent correctly, it means that some users see the wrong on-boarding flows.

After looking at the Analytics.NET code, I can see that all unexpected exceptions are not retried:

Analytics.NET/Analytics/Request/BlockingRequestHandler.cs

Line 289 in 1e0d510

Fail(batch, e, watch.ElapsedMilliseconds);

So my question is:

• would it be possible for you to retry exceptions like this?

This would clearly help in having more accurate analytics.

Regards,
Maxime