Re: [squid-users] http partial caching

Okay, I have confirmed my understanding most. Thank you very much.

This would be the final question.

When user X have downloaded the first 30MB of 100MB file, and still
keeps downloading the rest without disconnect.
In this moment, if user Y starts to download the same file, What happens?
Squid fetches same file again? or can pass the partial cache of user X?

Probably, the answer seems to be "it fetches again in both squid 2.x and 3.0."
My guessing is right? if so, how about squid 3.1 which supports partial data?

What I am asking is a situation like a class room which uses streaming video
for science education. Students clicks same contents at same time. But maybe
they dont see the video from start to end. They want to see a part which they
have interested in on demand. This is the reason I have asked about partial
caching.

I hope squid 3.1 solves all problems and will come soon ;).

                  ---- Okajima, Jun. Tokyo, Japan.

>On Wed, 23 Mar 2005, Jun OKAJIMA wrote:
>
>> case A. You are disconnected in the first 30MB. Then download the rest
>> with resuming. In this case, squid can cache a full 100MB file
>> at the end? and of course, the next users can benefit from it?
>
>What happens here depends on your quick_abort settings in squid.conf, and
>how the abort happened.
>
>If the connection between Squid <-> Origin server gets aborted then the
>content is discarded.
>
>> case B. While you are downloading the rest 70MB with resuming, If another
>> user is going to download the first 30MB, what happens? The user
>> can benefit from the 30MB cache?
>
>As above.
>
>Squid does not cache partial content (yet). As a result if there is only a
>partial content downloaded and the connection to the origin server gets
>closed for one reason or another the so far downloaded content is
>discarded.
>
>To mitigate some of this Squid has a feature to allow continuing
>downloading content even when the client has aborted. How aggressive Squid
>does this is controlled by the quick_abort parameters in squid.conf.
>
>I normally recommend to have these set to their strictest settings,
>forcing Squid to abort downloads immediately when the client aborts. I
>find there is too many issues with bandwidth wasting if this continuation
>of donloads is allowed.
>
>Regards
>Henrik
>
Received on Thu Mar 24 2005 - 03:19:59 MST