Re: squid in accelerator mode: invalidation of site contents

["Pablo García" <malevo@xxxxxxxxx>]

You can purge the complete content of the cache, just have to
Clear the swap.state file and restart squid.

echo "" > /var/cache/squid/swap.state

Hope this helps.

Regards, Pablo

On 7/12/07, martin sarsale <runa@xxxxxxxxxxxx> wrote:
> Kinkie wrote:
> > On 7/2/07, martin sarsale <runa@xxxxxxxxxxxx> wrote:
> >> Dear all:
> >> We're developing the new version of our CMS and we would like to use
> >> squid in accelerator mode to speed up our service.
> >>
> >>  From the application side, we know exactly when the data changed and we
> >> would like to invalidate all cached data for that site. Is this
> >> possible? maybe using squidclient or something.
> >>
> >> We can't do this purging url by url since it doesn't makes much sense
> >> (and we don't have the url list!). We want to wipe out every cached
> >> object for mysite.com.
> >
> > You can't do that on the squid side either, since squid doesn't index
> > objects by URL but by hash. The only way is to PURGE the relevant
> > object.
> >
> > You can reduce quite a lot the window of staleness by specifying in
> > every response the HTTP header:
> >
> > Cache-Control: s-maxage=XXX, public, proxy-revalidate
> >
> > (reference taken from: http://www.mnot.net/cache_docs/)
> > by choosing the right XXX value (the time in seconds before the object
> > expires) you'll be able to find the right balance between higher load
> > on the backend (smaller values of XXX) and higher chance of serving
> > stale content (higher values of XXX)
>
> (sorry for the delay)
> I understand what you are proposing with that header but IMHO that's
> valid for a 'dumb' system who cannot determine when it was modified.
> Since my system has this feature (I know the exact date the content as
> altered) I would like to let  Squid handling ALL the work except when is
> really needed.
>
> I understand about object hashes... does it hashes the full URL (ie,
> including domain?) because if domain was hashed separately I could purge
> the entire domain hash.
>
> Any other hints? unofficial patches? alternative products? squid forks?
>
> thanks