MOTOBIT.COM - ASP upload, IIS utility 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 HugeASP 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.
  
• HugeASP 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

See also

ScriptUtils