Why do some download links not show progress or overall size of file?

[fuzzybabybunny]

I've been given some download links and one of them is an .ova (Open Virtual Appliance) file that's 3.5GB.

When I download it I don't get a progress indicator.

It just goes
0KB... 200KB... 345KB.... 615KB... etc

It doesn't go like 615KB / 3.5GB... 1,343KB / 3.5GB... etc

It downloads fine in the Chrome Browser but it doesn't download via Android Chrome because it continually gets stuck in the "Retrieving File Size..." phase.

 

[DaveSimmons]

Use the developer tools in IE or firefox to capture the headers being sent from the server.

If the sending application doesn't send a content-length header, the browser doesn't know how big the file is.

 

[fuzzybabybunny]

The download is a direct link. It's an Apache server and I just dropped the file in there. First time I've heard anything about problems with content length or anything else. I have no idea how to tell Apache to add this header for a static file. Do you?

 

[Markbnj]

You probably have to use .htaccess to do this. The following article discusses (at some length) all the various things you can do with the .htaccess file. See the section on setting custom headers. You either want to write a rule that matches that one file and sets the known length, or better still write a rule that matches a class of files and use a server variable to get the content length value. Sorry I can't be more specific but I haven't done this in .htaccess before.

http://www.askapache.com/htaccess/htaccess.html

 

[fuzzybabybunny]

Hmmm... Thanks. Strange though that that behavior of sending the header isn't on by default though, no? I have another server and I checked the .htaccess and it doesn't specify anything about headers. Yet it sends them.

 

[ejjpi]

Check for transfer-encoding header. If the transfer encoding is chunked, then the Content-Length header will not be set

 

[Markbnj]

Hmmm... Thanks. Strange though that that behavior of sending the header isn't on by default though, no? I have another server and I checked the .htaccess and it doesn't specify anything about headers. Yet it sends them.

Is that other server also sending static files? When a file is sent back by some script, php or whatever, the script can modify/add headers to the response. But when a file is sent directly by apache (a static file that isn't processed by script, such as a .html, .css, .js, images, whatever) then it is up to Apache to create the headers.

Also, ejjpi's point about transfer encoding is a good one. If the server is set to chunk large files then there won't be a content-length header.