deleting the entire cache

Brad Fitzpatrick brad@danga.com
Thu, 1 Jan 2004 17:36:15 -0800 (PST)


Man, a whole slew of stuff.  Grep through the LJ source for LJ::MemCache
(which is our tiny wrapper package around Cache::Memcached) and you'll
find all the ways we use it.


On Wed, 31 Dec 2003, Tim Yardley wrote:

> Out of curiousity, what are the guidelines that LJ is using in determining
> what to cache and how to cache it?
>
> Are you caching structures? Arrays of result rows from the DB?
>
> /tmy
>
> -----Original Message-----
> From: memcached-admin@lists.danga.com
> [mailto:memcached-admin@lists.danga.com] On Behalf Of Brad Fitzpatrick
> Sent: Wednesday, December 31, 2003 3:04 PM
> To: memcached@lists.danga.com
> Subject: RE: deleting the entire cache
>
> We won't add that.  It doesn't work in a distributed way.
>
> Instead, make your "uid:43:*" keys be an array:
>
>         uid:43:foo = [ current_time, actual_value ]
>
> Then if you want to flush you do:
>
>         uid:43:flush_time = current_time
>
> Then your app does:
>
>         memcache::get_multi("uid:43:foo", "uid:43:flush_time");
>         // and compares foo->[0] and flush_time, killing uid:43:foo if
>         // it's old than the flush time
>
> Or something like that.
>
>
> On Wed, 31 Dec 2003, Justin wrote:
>
> >
> > I don't know C well enough to be able to tell if this is do-able without
> > slowing down memcached.
> >
> > Would it be possible to have something like a flush_match command?
> >
> > Say I have a bunch of keys like "uid:43:userinfo", "uid:43:profile1", etc
> > etc... It'd be super-cool if I could do something like "flush_match
> uid:49",
> > and memcached nukes all keys that start with uid:49.  I'm not talking
> about
> > a fullblown regex, just very simplistic front-of-string matching.
> >
> >
> >
> > -----Original Message-----
> > From: memcached-admin@lists.danga.com
> > [mailto:memcached-admin@lists.danga.com] On Behalf Of Brad Fitzpatrick
> > Sent: Tuesday, December 30, 2003 2:36 PM
> > To: memcached@lists.danga.com
> > Subject: Re: deleting the entire cache
> >
> > It does.
> >
> > I might as well make a new release (even though it'll be boring and
> > small).  One sec.
> >
> >
> > On Tue, 30 Dec 2003, Chris Ochs wrote:
> >
> > >
> > > The intended use we have for memcached is to cut down on queries to our
> > > database for user configuration information that is needed by the
> > > application for every request.   When configuration variables are
> updated
> > in
> > > memcache I need a way to delete all old variables, but without knowing
> > what
> > > they are.   I just want to wipe the memory and start fresh so to speak.
> > > Does the new flush command in cvs do this?  If so is there a tarball of
> > the
> > > current cvs version?
> > >
> > > Chris
> > >
> > >
> >
> >
>
>