Well Robert, if I remember correctly, two different methods for establishing/limiting file sizes in uplodas have been suggested in previous discussions. One was a javascript and one was an external process using someone's custom made taf. So it is possible to limit file sizes on uploads - though as you say, probably not foolproof, but your main point still stands, and it does seem that large files are going to cause serious slowness on servers.

This seems to be a perennial problem though - I remember a couple of people in previous discussions stated that Cold Fusion had a more reliable method of doing this which was built into CF - maybe this is one of the things that should be put on the wish list for Witango. However, a java applet which used ftp, invoked from the web page, which handled the transfer separately would seem to be a good way of achieving this.

Anyone want to write one?
Garth


This is one of the reasons for my apprehension and thorough testing before making the app live.

I normally do not use HTTP upload, but it is quick and easy solution for certain clients.

In my testing, there also seems to be a memory leak in the dllhost program (must test further to be sure), and searching on the web, this has been a problem for others. Also, in my testing, while one file is being uploaded, the OS releases some resources, but there is a definite slowdown, with two files uploading, the server becomes almost completely unusable. I am testing on a AMD XP 2100 processor with 256 meg DDR ram.

This would lead me to make the decision that HTTP Upload should NEVER be used. Small files may not be a problem, but there is no foolproof method for limiting file size in an http upload. So you may write an app that is only supposed to accepts small text files, or thumbnails, but what if a user chooses the wrong file, and it is 50 megs?

I have not tested it yet with servers running on other platforms, but it would seem that NOT using http upload would be a good suggestion, especially in windows.

Robert.

On Sunday, March 23, 2003, at 05:50 PM, Phil Wade wrote:

You should be careful uploading large files through any web application
server, especially when they are client server.  If you look at the  route
that the file takes in memory it is copied quite a few times so the  larger
the file the more work that needs to be done.  A typical scenario  would go
like this.

(This has been generalised)

File submit via form
File read into browsers memory
File sent to web server over network
File read from network buffer and passed to web server memory as  postarg
File passed to app server client and wrapped for sending to app server
File sent to app server from client
File unwrapped by app server memory so it can be accessed as @POSTARG
File saved to disk

So as a minimum the file has been shuttled around in memory around 7  times.
Add to this the encoding that may happen if debug/logging is turned on  so
that the variable that contains the data is displayed in the debug  trace/log
and it may be greater.

Remember that the client runs in the web server's memory space so this  can
make the CPU and memory of the web server process appear to race as it  is
encapsulating the postarg to be sent to the server..

Now that the client and server are preemtive, they will attempt to  take as
much CPU as they have available to them.  Both the client and server  should
yield to other processes requesting cpu so the machine should not  become
unresponsive.

As a rule of thumb, you should try and get the file to the server  using the
shortest path possible and should save it to disk asap.  Using http is  not
the most efficient way of doing this.

Phil


On 24/3/03 12:17 PM, "Garth Penglase" <[EMAIL PROTECTED]> wrote:


It may be a Windows issue not an IIS 5 issue.
Any thoughts Phil/Sophie?
Garth

Robert

I tried this on a XP box with apache. IT has 640 megs of ram and a
2.0ghz p4 and my cpu usage went up to 100% so its not an issue with  IIS.

Mike D

-----Original Message-----
From: Robert Garcia [mailto:[EMAIL PROTECTED]
Sent: Sunday, March 23, 2003 12:29 PM
To: [EMAIL PROTECTED]
Subject: Re: Witango-Talk: HTTP Upload

I haven't done enough testing yet, but I don't think this is a  Witango
issue, but a IIS 5 issue.

It would really help if someone had a IIS 5 server using http upload
that can test this, so I dont have to set that up.

Robert.

On Saturday, March 22, 2003, at 11:16 PM, Garth Penglase wrote:

I'd be very interested as to whether this is purely a Windows/Witango

issue or if it relates to OSX and other platforms. I agree that it is

totally unacceptable that there is anything more than a few percentage

 cpu usage, and this will significantly affect performance on my
 servers when I upgrade to Wi5 in the next week or so, as I have a
 number of apps that will require this service.

 Maybe With has a comment on this one....??
 Garth

Thats not the issue. The issue is having a solution for a client that

  is not savvy enough to use an ftp client. I already use webdav in
 such  a way that they could connect with a webfolder from  windows, or

  directly from OS X. But these are people that can only be  expected
 to  work with a single interface, and click a few buttons. Using  HTTP

  Upload is very simple and suits that. But HTTP Upload has other
 problems, and this CPU Usage issue now knocks it completely off my
 list.

Robert.

On Saturday, March 22, 2003, at 05:10 AM, Michael Dittbrenner wrote:

Robert

Why not just put up a ftp server instead of using http. Ftp protocol

 is
 a lot faster than http for uploading and puts less strain on the
 server.
 Windows 2000 comes with a ftpd built in and if your client  doesn't
 have
 a ftp client they can download a trial from like  www.globalscape.com

  for
 cuteftp.

Michael Dittbrenner


-----Original Message----- From: Robert Garcia [mailto:[EMAIL PROTECTED] Sent: Saturday, March 22, 2003 6:59 AM To: [EMAIL PROTECTED] Subject: Witango-Talk: HTTP Upload

 I normally don't use http upload for many reasons, but I had to  do a
 quick and dirty solution for a client. They must be able to  upload
 MP3
 files to our servers. The files range from 10-20 megs. Before I  put
 this into production, I wanted to test the load it would put on  my
 servers. My app uses witango to accept the file argument, and  write

it
to a file where I want it. I am running Witango 054 and IIS 5 on
windows 2000. During the upload, the server pegs 100% CPU usage,
dllhost.exe and inetinfo.exe being the culprits. Witango only  spikes
 when the upload is done to write the file.

 Since I have only used http upload with very small files in the
 past, I
 have never noticed this. This is totally unacceptable. If I  upload
 the
 same file to the same IIS Server using IIS WebDav, it doesn't  break
a
sweat, 1-2% CPU Usage. I can't recall every testing this with other

 web
 servers, does anyone else have any info with apache or Webstar?

 It looks like I will have to write a custom desktop app for this
 client's admin, which I did not want to do. If anyone knows of  any
 IIS
 5 tweaks that may help, I would appreciate it. My systems are
 completely patched once a week.

--

 Robert Garcia
 President - BigHead Technology
 CTO - eventpix.com
 2781 N Carlmont Pl
 Simi Valley, Ca 93065
 ph: 805.522.8577 - cell: 805.501.1390
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 Robert Garcia
 President - BigHead Technology
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 2781 N Carlmont Pl
 Simi Valley, Ca 93065
 ph: 805.522.8577 - cell: 805.501.1390
 [EMAIL PROTECTED] - [EMAIL PROTECTED]
 http://bighead.net/ - http://eventpix.com/ - http://theradmac.com/

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 _
 TO UNSUBSCRIBE: send a plain text/US ASCII email to
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Robert Garcia
President - BigHead Technology
CTO - eventpix.com
2781 N Carlmont Pl
Simi Valley, Ca 93065
ph: 805.522.8577 - cell: 805.501.1390
[EMAIL PROTECTED] - [EMAIL PROTECTED]
http://bighead.net/ - http://eventpix.com/ - http://theradmac.com/

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--


Robert Garcia
President - BigHead Technology
CTO - eventpix.com
2781 N Carlmont Pl
Simi Valley, Ca 93065
ph: 805.522.8577 - cell: 805.501.1390
[EMAIL PROTECTED] - [EMAIL PROTECTED]
http://bighead.net/ - http://eventpix.com/ - http://theradmac.com/

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