Re: Introduction / accelerator feature ideas

fre 2003-02-21 klockan 15.03 skrev Flemming Frandsen:
> Robert Collins wrote:
> > I certainly hope it's uncommon!
>
> I don't think it is, it's a natural assumption that the same user will
> not be making the same request twice at the same time.

Not for anyone who have ever observed users in real life.. If nothing
happens for a few seconds they click again, thereby repeating the same
request.

This is how humans behave. Not at all restricted to web applications,
but is a fact in almost all interactions with humans.

> Yes, you are right, but if I put the syncronisation in the webserver I
> have already lost because, I'll have an apache process sucking mud
> waiting for the proper locks.
>
> The only way to correctly fix this in the application is to check if the
> job is already done and react intelligently to that, come to think of it
> that might be a whole lot better solution.

> I have seen the light and will shut up about that point now.

You also have the option of checking for client aborts, and quickly back
out from the request when a aborted request is detected..

> > squid will stop serving once write() returns an error.
>
> Yes, but that will not happen before the request has been run and that
> means that you have just run a request for a user who has given up and
> submitted a new one, iow: because the content can never be cached you
> have lost.

Again: See the half_closed_clients. If set to off Squid will immediately
detect when the client aborts the request and signal the abort to your
server by closing the connection.

> Luckily it's rare to have people who use proxies and those that are
> deserve to be punished ;-)

Grr...

> No not really, but it really does seem like very very few users sit
> behind a proxy and in the situation where people are likely to need this
> hack they are also likely to have read the pre-sales-instructions that
> tell them to turn off their proxy.

Most users who are behind a proxy do not have the option to turn off
their proxy.

Most major corporations enforce the use of proxies to reach the web, for
many reasons, and do not provide means for their employees to bypass the
proxy unless they have very special and business related reasons why.

Very few home users are behind proxies. Of the few who are maybe 5% can
select to not use the proxy, the others have the use of a proxy enforced
by their ISP.

> Hmm, how, where? I'd be more than happy to spend some RAM to get more
> free apaches.

Look for READ_AHEAD_GAP

Regards
Henrik

-- 
Henrik Nordstrom <hno@squid-cache.org>
MARA Systems AB, Sweden