Re: Throttling cached content.

> On Wed, Nov 21, 2007, German Gomez wrote:
>> Hello,
>>
>> I've reading through the list and found several references to this
>> subject, how to limit bandwidth for cached content, and the only
>> solution
>> was to use QOS inside linux kernel. We have a remote accelerator proxy
>> and would like to limit the bandwith for big files so smaller ones get
>> dispatched as fast as possilbe but large one do not fill up your
>> bandwidth.
>
> ok.
>
>> I have been reading through the code of delay_pools.c and it seems that
>> it
>> should be possible the use the same infrastructure for limitting the
>> server bandwidth shouldn't it??

The code itself maybe. However the side-effects of using it should be
checked and tested well.
I believe the data is buffered by the kernel on receipt to a large degree
these days, whether the client app reads it out or not. Throttling the
inbound side of the transaction would cause these buffers to fill faster
than emptied and an overflow can be expected at some point outside squid.
Whether any specific OS handles that nicely or not is an ongoing
networking problem.
The catch-22 is that throttling in this manner in a client app does not
actually save any bandwidth until the OS buffer is has reached overflow.

My opinion is that the joint application of collapsed-forwarding and
improved caching is the better approach to take when server-side bandwidth
is a consideration.

/2c

> I suppose we should replicate the
>> delayClient() function and attach it to the server side. Is there any
>> ongoing project to add this kind of feature?? If not, is there any dev
>> documentation to start understanding current squid?
>
> There isn't anything all that helpful at the present time. Amos has been
> working on automated documentation builds but they won't help you figure
> out how the "bits" hold together yet.

Well, nothing very easy to read anyway. You can sort of do it by following
the Referenced-By and References lists attached to each object. But
keeping that in wetware can be tricky with any messy or not yet understood
code.

(not to self: get the dot function graphics going.)

Amos

>
> There's no current project to implement that functionality. Please add
> your request in the Squid bugzilla as a "feature request".

Or jump in yourself and give me a hand with the 'docs' branch. :-)

Amos

>
> Projects only move forward if there's funding or someone gets interested
> in it.
>
>
>
> Adrian
>
>
Received on Wed Nov 21 2007 - 18:35:30 MST