Browser hangs when using TransferFile on very large files

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Support Knowledge Base, Article 212

Product

FileUp

Version

2.x, 3.x

Title

Browser hangs when using TransferFile on very large files

Problem

When using FileUp's TransferFile or TransferBlob methods to stream very large files to a client, you may observe sharp spikes in memory usage and the appearance that the browser is hanging. You may also receive low virtual memory warnings on the server.

Starting with ASP 3.0, output buffering is turned on by default. Under normal circumstances this is advantegeous. However, when downloading large files it is adviseable to begin sending the file to the client immediately without buffering it.

Solution

Turn off the ASP response buffer by adding Response.Buffer = False to your code:

<% @Language = "VBScript" %>
<% Response.Buffer = False %>

Add this line near the top of your ASP page. It must occur before any HTML or Response.Write statements. If you turn off the response buffer, make sure to remove any instances of Response.Clear or Response.Flush from your code as they will cause your script to fail.

Created : 12/1/2002 12:00:00 AM (last modified : 9/21/2001 5:01:00 PM)

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