Upload progress bar does not work. Article

Question

       I'm attempting to try your huge asp upload code on a Windows 2003 server in IIS5 mode and while my file uploads work, the progress bar never shows any information. It clicks w/ the refresh of the page but all all progress bars show 0 for size of files and total. Any help on this issue would be appreciated.

Resolution

       I test Huge ASP upload with IIS5, IIS6 and IIS7 and I found some properties, which have impact to progress bar:

• UploadReadAheadSize (UploadReadAheadSize on Google)
  The value is 48kB by default. Upload progress does not work if the first UploadReadAheadSize bytes is not red (But it should work after the 48kB). You should set this value to zero to get progress work from zero. Please run next command from command line (You can find adsutil.vbs script in IIS admin scripts). Use the command o web site with upload.
  'cscript adsutil.vbs SET W3SVC/1/Root/UploadReadAheadSize 0' You can also use Metaedit metadata editor to set this property.
  
• Session
  Session serializes communication between client and server, so second window with upload progress is not updated, since the upload is stopped.
  Please remove code which uses session from your global.asa, or move upload to another application (create own global.asa for upload)

  <SCRIPT LANGUAGE=VBScript RUNAT=Server>
  Sub Session_OnStart
  Session.Timeout=25
  End Sub
  </SCRIPT>
  

  The progress.asp has @EnableSessionState=False, so such code can raise problem (error) which cause progress not to work.
  
• Server-side debugging
  Server side ASP debugging serializes connections in some conditions, so progress also do not work. Please switch off server-side debugging. (home directory tab, configuration butto, debugging tab for the site)
  
• Frames
  HTTP 1.1 specifies only two active connection to one host. So there is no free connection for progress if you use frames for upload window.
  
• Huge ASP upload and IIS6 - Number of worker processes.
  See app pool properties, performance tab, maximum number of worker processes. The number must be 1. progress.asp and primary upload window (Upload-Progress.ASP) must run in the same process. You can create own application pool for the upload with only one worker process.
  
• URLScan and other security utilities, POST limits
  URLScan limits POST size and the limit is also applied to upload. Check also other IIS and ASP POST limits (Upload - Files and forms with large/huge size.)
  
• PureASP upload specific - temp folder
  PureASP upload script uses temp folder to pass data from a primary upload window to secondary progress window. User account running ASP must have read/write rights to the server temporary folder for progress. You can set appropriate rights for the temp folder or change next line in _upload.asp include to any temp folder:

  		TempFolder = fs.GetSpecialFolder(2)
  

Resolution for session problems

      HTTP 1.1 specifies only two active connection per one host. So there is no free connection for progress if you use frames for upload window, or several browser windows communicating with server. You can specify another host for upload script (for example http://www.yoursite.com/upload/Upload-Progress.ASP) and http://upload.yoursite.com/upload/progress.asp for the progress window. The www.yoursite.com and upload.yoursite.com hosts should lead to the same IIS server, to the same application/virtual server.

See also

Upload - Progress bar indicator

ScriptUtils.FAQ for Huge ASP file upload and scriptUtilities

Frequently asked questions about ScriptUtilities, Pure-ASP and Huge-ASP upload functionality.

ScriptUtils

Huge ASP upload is easy to use, hi-performance ASP file upload component with progress bar indicator. This component lets you upload multiple files with size up to 4GB to a disk or a database along with another form fields. Huge ASP file upload is a most featured upload component on a market with competitive price and a great performance . The software has also a free version of asp upload with progress, called Pure asp upload , written in plain VBS, without components (so you do not need to install anything on server). This installation package contains also ScriptUtilities library. Script Utilities lets you create hi-performance log files , works with binary data , you can download multiple files with zip/arj compression, work with INI files and much more with the ASP utility.