Re: Partial contenet,206

On 1/31/2013 4:21 AM, Amos Jeffries wrote:
>
> Have you actually sighted use of the Range: HTTP headers in Youtube
> traffic? and have you verified that (2) beow is no longer happening (as
> of 2 year ago it was)?
>
> In my experience ...
> 1) they do not use HTTP Range: headers on most of the videos (at least 2
> years ago it was rare).
> 2) they prefix each snippet of video with FLV meta headers
> 3) several of the HD video encodings used are VBR encodings based on
> IP-layer speed detection.
>
<SNIP>
I know about the meta headers.
I was referring to the actual thing that two different http
objects(urls) are in-fact a range of the same video.

>>
>> So we can might try to store partial responses in a cache object
>> specifically for partial response.
>> This is where my question was about size since most of the clients
>> will request more then just 8k chunk and we can even do some
>> statistics from existing live server logs to make sure of it.
>>
>> This is the most practical way in the current situation.
>> This indeed will open a small weakness in cases which there are two
>> clients requesting the same object one with partial content request
>> and the other a full response.
>> A solution for that can be for squid to learn if it dosn't know how to
>> serve partial content from a complete file.
>
> Squid already has this capability. For the range_offset_limit and HIT
> Range: serving capabilities.
> This is mainly why I was suggesting wait on Collapsed Forwarding,
> because you might find it easier to collapse the two requests down and
> service the Range: request out of the full requests response. Or service
> the full request using two parallel 'filler' requests around the
> underway Range request - together the three background requests
> consisting of a full object fetch.
>
>
> Amos
I suppose this is worth to wait for.

-- 
Eliezer Croitoru