Sensing failed downloads

[Buddy Ackerman]

Is there any way to determine that a user received a downloaded file. I'm
developing a service that sells documents (like PDF books) and I need to
have a way to determine if the buyer actually got the document. Is there
any way to determine is the client received the full download?

--Buddy

 

[Assaf]

One crude way that comes to mind is using the IIS log or a custom app log:
Capture the buyer's host IP address and then search the log for a GET on the
that address, date, document name and a status code of 200.

2004-04-08 23:33:08 W3SVC1 SERVER5 233.81.31.14 GET /pulbicdocs/MyDoc.pdf -
80 - 154.199.45.213 Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.1) -
mycompany.com 200 0 64

I'm sure there are more elegant ways to accomplish this task but that will
probably work.

HTH.

- Assaf

 

[Buddy Ackerman]

That doesn't necessarily guarantee that the whole file was downloded though
does it? Also I hsould have pointed out that the file is not being access
directly. I have and ASP.NET page that reades and attcahes the file to the
response. Here's what I'm doing.


response.contenttype = "application/pdf"
header = "attachment;filename=" & filename
Response.AddHeader("Content-Disposition",header)
Response.WriteFile(FileName, StartPos, FileSize)


Anyway to know that the download has been interrupted?



--Buddy

 

[Evert Timmer]

Hi buddy,

I do not believe that is possible to be a 100 percent sure of this.

Consider the use of proxy servers

A lot of users may be connected using a proxy server and it might be
possible for this server to continue and finish the download, long after
your user has "crashed" his machine, or interrupted the download in any
other way.

Maybe an email to the user with a reporting service for download errors
could help you out.

Evert