Upload - Files and forms with large/huge size.
          Article, Upload - Files and forms with large/huge size. 
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Upload - Files and forms with large/huge size.
 Main idea for big uploads   

      Upload components (including ASPNet HTMLInputFile) usually use memory to store temporary upload data. It is a problem, if you are uploading very large files.

      Huge-ASP upload works with unique hi-performance technology, which lets you read upload source data in small data blocks (Request.BinaryRead) and store the data on temporary disk folder - this is automatic Huge-ASP upload work, of course. You can specify size of a source data block and maximum amount of memory to store data (to store small uploads in memory).

      For example, HTMLInputFile from ASPNet takes around 5MB of memory to upload 1MB file. You will need at least 500 MB of a free memory if you have 10 clients uploading one 10MB file with ASPNet HTMLInputFile upload control. Huge-ASP upload takes less than 1MB (one megabyte) of memory to do the same action (and 100MB disk size to store temporary data, of course).

 Important points for huge uploads with Huge-ASP upload   

1. Server.ScriptTimeout and ScriptUtils.ASPForm.ReadTimeout property.
      Big uploads take much time to complete. Next table contains approximate time values to upload files:

File
size

Line speed
[kb/s]

Upload
time

Upload time [s]

1MB 33 00:04:33 273
10MB 33 00:45:27 2727
100MB 33 07:34:33 27273
1MB 64 00:02:05 125
10MB 64 00:20:50 1250
100MB 64 03:28:20 12500
1 000MB 64 34:43:20 125000
1MB 256 00:00:35 35
10MB 256 00:05:52 352
100MB 256 00:58:36 3516
1 000MB 256 09:45:56 35156
1MB 8000 00:00:01 1
10MB 8000 00:00:11 11
100MB 8000 00:01:52 113
1 000MB 8000 00:18:45 1125
2 000MB 80000 00:03:45 225

      Huge-ASP upload has a great performance - it lets you really accept 2GB files in 200second on 100Mb/s Ethernet line. But you have to set ScriptTimeout value to have enough time to transfer data and some time more to process uploaded files on server-side. If you want to accept up to 1GB uploads from min. 256k leased lines, set at least: 

      Server.ScriptTimeout = 40000
      There is no problem to set a big value for ScriptTimeout - Huge-ASP upload checks client connection during upload and server-side upload process is stopped when client interrupts upload.
      You can also change this value by some dynamic algorithm with parameter of source form size. For example, on 10Mb/s Ethernet line (real 8000kb/s, 1MB/s):
Dim ScriptTimeout, TotalBytes
TotalBytes = Request.TotalBytes
'TotalBytes/1000000 - time to transfer data
'TotalBytes/5000000 - time to save data on server-side

ScriptTimeout = 100 + TotalBytes/1000000 + _
 TotalBytes/5000000
Server.ScriptTimeout = ScriptTimeout
2. ScriptUtils.ASPForm.SizeLimit Size limit
      Second important value is a ScriptUtils.ASPForm.SizeLimit property. Huge-ASP upload has no limit set by default. It means you can upload and accept any files up to 2GB of size (2^31-1B; Huge-ASP upload can accept up to 4GB, but you will probably not have a client which let's you upload files bigger than 2GB ...).
      Internet Explorer (from v 5.0) and Netscape Navigator let's you upload files with size up to 2GB also.
      Be careful to have this value without limit - upload scripts are possible point for DOS attacks. If you have public upload script, set lower value rather. You can also create some dynamic algorithm to limit upload size based on logged on users, local IP addresses, etc.  
Form.SizeLimit = GetLimitFromDB(LOGON_USER)
      Please see ScriptUtils.ASPForm.Upload - Monitor and handle upload state/result article to handle "upload size exceeds the limit" state.

3. ScriptUtils.ASPForm.TempPath Temporary path
      Temporary upload data are stored in predefined folder. Please, set a folder with adequate free size. For example, if you have up to 10 clients uploading up to 1GB file, you need to have 10GB temporary folder to store temporary form data (and second 10GB free space on destination disk/store).

4. Progress bar
      Use progress bar every time you want to accept big uploads. Client browsers have no progress indicator by default. And clients-people know probably nothing about this problem. You will have many people, which will try to upload same files again and again (they will think nothing changed after "upload button" click) - without progress bar.
      Huge-ASP progress bar is open immediately after Form submit button and client can see that something happened - and can see progress of upload.

5. Use low application protection (inprocess ASP) 
      Only for experienced users: ASP has a better performance if running as inprocess (in inetinfo.exe). The performance difference is 50%, see ScriptUtils.ASPForm.Upload - performance tests.. You can safely run Huge-ASP upload in ASP application running in inetinfo.exe if you have only one application on the computer. There may be some complications with one or more other isolated (out-of-process) ASP applications on the same machine. See MS help about low/hi application protection.
      

maxRequestLength - Maximum request length exceeded - IIS6

Symptoms

When you try to use the ASPForm object to upload a large file with ASP and IIS6, the file may not be uploaded. This problem occurs because the default value for the maxRequestLength parameter in the <httpRuntime> section of the Machine.config file is 4096 (4 megabytes). As a result, files that are larger than this value are not uploaded by default.

Resolution

To resolve this problem, use one of the following methods:
  • In the Machine.config file, change the maxRequestLength attribute of the <httpRuntime> configuration section to a larger value. This change affects the whole computer.
  • In the Web.config file, override the value of maxRequestLength for the application. For example, the following entry in Web.config allows files that are less than or equal to 8 megabytes (MB) to be uploaded: 
    <httpRuntime maxRequestLength="8192" />

    • Web resources

    http://support.microsoft.com/default.aspx?scid=kb;EN-US;295626
    http://www.google.com/search?q=maxRequestLength

     Other references   

    ScriptUtils.ASPForm.MaxMemoryStorage
    ScriptUtils.ASPForm.ChunkReadSize 
    ScriptUtils.ASPForm.Upload - Monitor and handle upload state/result

      Other links for Upload - Files and forms with large/huge size.
    ScriptUtils
          Easy to use, hi-performance ASP file upload component with progress bar indicator. Let's you upload multiple files with size up to 2GB to a disk or database along with another form fields. Works with large posts, any character set (including unicode utf-8). Contains one-click multiple files/folders download with on-the-fly compression (Using BinaryWrite/BinaryRead).
          Hi-performance text file logging for ASP/VBScript/VBA applications. Lets you create daily/weekly/monthly log files with variable number of logged values and extra timing and performance info.
           Lets you work with safearray binary data in VBS/JS. It also enables conversion between binary and String data using several code pages. ZLib compress and uncompress functions. Lets you transfer files using compressed stream from a client to server using IE.
          This library also enables calling of some Kernel and Advapi functions (performance, timing, sleep, configuration ...) and enables native work with INI files.

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