On Tue, 1 Jun 2010, Jonathan Rochkind wrote:
> Accept-Ranges, I have no idea, I don't understand that header's purpose
> well enough. But SRU also provides a query param for that, it seems less
> clear to me if that's ever useful or justifiable.
Accept-Ranges is a response header, not something that the client's
supposed to be sending.
The client sends a 'Range' header (with an optional 'If-Range' if you're
concerned with the resource having changed), and in response, the server
sends a 206 status with a 'Content-Range' header.
See
http://labs.apache.org/webarch/http/draft-fielding-http/p5-range.html
...
I only know of two values for 'Accept-Ranges' -- none (ie, I don't accept
partial downloads) and bytes, so for incomplete downloads you can start
where you left off. If you know the file's excessively large, I guess you
could use it to transfer it in parallel to abuse the TCP congestion rules.
(or if you have a way of knowing that there are multiple mirrors, to
spread the load across servers).
-Joe
