Re: [squid-users] read_ahead_gap

Thanks. How much do I have to worry about this from a memory
perspective (i.e., does each connection have this much memory
allocated for a buffer, or only allocated when there's actually a gap)?

Cheers,

On 2007/11/15, at 12:01 PM, Henrik Nordstrom wrote:

> On ons, 2007-11-14 at 11:49 +1100, Mark Nottingham wrote:
>> I'd like to double-check the semantics of read_ahead_gap.
>>
>> AIUI, Squid will buffer up to that much data on both requests and
>> responses, in addition to the TCP send and receive buffers.
>
> responses only.
>
>> So, if I have (for the sake of argument) 16K TCP read buffers, 24K
>> TCP write buffers, and 32K read_ahead_gap, a pathological request
>> case might look like:
>>
>> client ---> [ 16K worth of TCP read buffer ] --> [ 32K internal Squid
>> buffering ] --> [ 24K worth of TCP write buffering ] --> server
>
> yes, if reversing the picture.
>
> The request forwarding path is slightly different, with internal
> buffers
> of only 8KB under normal conditions. There is no tunable knob for
> this.
>
> Regards
> Henrik

--
Mark Nottingham       mnot@yahoo-inc.com