On Fri, 2010-03-12 at 11:37 -0800, Michael Shadle wrote: > On Fri, Mar 12, 2010 at 4:41 AM, Ashley Sheridan > <ash@xxxxxxxxxxxxxxxxxxxx> wrote: > > > I've noticed that large uploads over http seem to behave a little > > unpredictably at times, and aren't something I'd rely on. FTP is > > definitely the way to go, and there are plenty of Java applets that > > allow you to do this. > > FTP is not a realistic option, for a multitude of reasons. > > a) mapping an HTTP request and user -> FTP account / "pick this file up" > b) firewall issues > c) additional services having to be enabled and routed to on the server side > > While I do agree FTP is FILE transfer protocol, it still isn't the > right solution IMHO. Ideally, HTML5 will provide a more industry > standard method (IIRC, a coworker already pointed out something in the > spec for it, but I forget) > > A very workable solution we've came up with has been using Google Gears + PHP. > > Re-using the browser and HTTP conversations provides us multiple benefits: > a) Cookie support - to identify the user > b) supports HTTP and HTTPS > c) Firewalls are not an issue - reuses the same proxy settings > > The difference between standard file upload using a single POST vs. > our method is key - it's chunking the file. Google Gears has this > support, Java can too; send up portions of the file at a time, and > either glue it together on the fly on the server, or take all the > chunks and merge them all at once at the end. By doing it in a chunked > format, it allows us to also re-transmit failed chunks and treat files > of any size in "bite size chunks" - with a little bit of Javascript, > PHP and Gears, we can support files of any size (within filesystem and > OS limits) and it does not require -any- tweaking of the webserver. It > is chunks of data sent to the server using standard POSTs and small > enough to fit under even small PHP and webserver memory limits (and > could always be configurable) - no more suhosin.memory_limit, > memory_limit, post_max_size, upload_max_filesize to fuss with. > > It's a shame that Google had to decide to stop developing and > maintaining Gears. It was a lightweight, perfect solution. > > We're working on a Java-based version instead now. Lightest footprint > we can possibly get in Java, but it's the only applet language that > has all the support we need for chunking, cross-browser, > cross-platform, etc. > > I believe our plan is to release it out to the public so people can > enhance it, use it, do whatever... > > For now though, Gears works pretty awesome for us, a handful of our > users have complained though Gears won't install for them (not sure > why) and there is no support for Snow Leopard, I believe. So we're > starting to hit the point where it isn't our magical solution anymore. > It's not much trouble to map the FTP to a file and have the right permissions, and FTP is a doddle to set up on a server. I'd say a darn sight less work than rolling your own mechanism in Java. Lastly, I don't think firewalls are that big an issue, as most firewalls I've seen will allow outgoing FTP connections from a users computer by default. Thanks, Ash http://www.ashleysheridan.co.uk
