I checked on this internally, and it seems that the server writes the bytes from the input stream (the file being uploaded) directly to the file system, and more specifically to a temp file that then gets moved to the specified directory (at least this is the behavior of MX and ColdFusion 5). From a security standpoint, this is the right behavior. It might technically be slightly faster if the server were to try to buffer the file in memory, however 1) this is a huge security risk as it would clearly be a denial of service attack opening, and 2) realistically, it probably would not affect the speed considerably if at all since the bottleneck is most likely bandwidth rather than the process of writing the bytes to the file system. In fact, saving the file is probably one of the fastest steps in the process.
As far as why uploads are timing out, I'm really not sure, except that I've seen this before, and it is often a client issue, not an issue with the server. In theory, the client should not time out as long as data is moving from the client to the server, however in practice, I have seen several inexplicable ClientDisconnectExceptions in various projects in the past. A ClientDisconnectException is a Java exception that gets thrown when the client disconnects before it has finished writing all of the request to the output stream. Wherever a client has the opportunity to upload a large file (anything over 1MB), you are likely to see these errors. Possible causes include users intentionally stopping the download (the client has no friendly way to convey to the server that the user simply changed his mind), clients timing out due to pitiful dial-up speeds, connections being dropped by ISPs or saturated 802.11b networks, browsers crashing, computers crashing, people tripping over power cords, etc. To be honest, I don't know, but I can confirm that it should not be an issue of running out of RAM and does not present a security vulnerability in ColdFusion MX. Christian On Monday, January 20, 2003, at 02:53 PM, Joshua Miller wrote: > I thought it saved it as a TMP file ??? Does it actually store in RAM ? > > Joshua Miller > Head Programmer / IT Manager > Garrison Enterprises Inc. > www.garrisonenterprises.net > [EMAIL PROTECTED] > (704) 569-9044 ext. 254 > > *********************************************************************** > * > ************* > Any views expressed in this message are those of the individual sender, > except where the sender states them to be the views of > Garrison Enterprises Inc. > > This e-mail is intended only for the individual or entity to which it > is > addressed and contains information that is private and confidential. If > you are not the intended recipient you are hereby notified that any > dissemination, distribution or copying is strictly prohibited. If you > have received this e-mail in error please delete it immediately and > advise us by return e-mail to [EMAIL PROTECTED] > *********************************************************************** > * > ************* > > > -----Original Message----- > From: Todd [mailto:[EMAIL PROTECTED]] > Sent: Monday, January 20, 2003 2:47 PM > To: CF-Talk > Subject: Re: CFserver Timesout when uploading a 13mb file > > > RAM -- CFFILE I believe uploads into pure ram before it dumps to disk. > > ~Todd > > At 11:40 AM 1/20/2003 -0800, you wrote: >> I have a 13mb .doc file being uploaded using a simple CFFILE. The >> server timesout. After I zipped the file down to a 9mb file, it was >> OK. Does anyone know what triggers the limitation? >> >> Thanks >> Michael > > > ---------- > Todd Rafferty ([EMAIL PROTECTED]) - http://www.web-rat.com/ > Team Macromedia Volunteer for ColdFusion > http://www.macromedia.com/support/forums/team_macromedia/ > http://www.devmx.com/ > > ---------- > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/cf_lists/index.cfm?method=subscribe&forumid=4 FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Your ad could be here. Monies from ads go to support these lists and provide more resources for the community. http://www.fusionauthority.com/ads.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
