Re: [PATCH 2/2] add deps to all software that use memcached to have it installed and managed

[Pierre-Yves Chibon]

On Tue, Apr 29, 2014 at 10:01:49AM -0600, Kevin Fenzi wrote:
> On Tue, 29 Apr 2014 07:28:30 +0200
> Pierre-Yves Chibon  wrote:
> > On Thu, Apr 17, 2014 at 10:28:37PM +0200, Pierre-Yves Chibon wrote:
> > > On Thu, Apr 17, 2014 at 08:48:00PM +0200, Michael scherer wrote:
> > > > On Thu, Apr 17, 2014 at 10:19:02AM -0600, Kevin Fenzi wrote:
> > > > > The first patch here looks fine to me... but the second one
> > > > > isn't going to work I don't think.
> > > > >
> > > > > Those services use memcached, but they use our existing
> > > > > memcached03/04 instances that are still in puppet, not local
> > > > > memcached.
> > > >
> > > > Not all.
> > > > Nuancier seems to use localhost :
> > > > http://infrastructure.fedoraproject.org/cgit/ansible.git/tree/roles/nuancier...
> > > >
> > > > So does pkgdb :
> > > > http://infrastructure.fedoraproject.org/cgit/ansible.git/tree/roles/pkgdb2/t...
> > > >
> > > > ( unless i missed something and pkgdb2 and nuancier run on a
> > > > memcache server )
> > >
> > > Nuancier and pkgdb2 could be moved, it's just a matter of adjusting
> > > the configuration file.
> > > pkgdb2 has memcache but iirc, it doesn't do much with it. I tried
> > > to speed up some of the API calls with it but it wasn't really a
> > > clear win, so I'm not sure it actually uses memcache at this time.
> >
> > I correct myself, pkgdb2 still uses memcache for its integration with
> > FAS.
>
> So, I was kind of wondering if we should have some kind of best
> practice around memcache or guidelines for Fedora Infrastructure
> applications.
>
> a) When should you use memcache?
>
> b) When should it be external host vs local?
>
> c) How large should it be?
>
> I think my wild ass non application developer answers would be:
>
> a) When it's easy to integrate and you have things that would speed up
> by using it.
>
> b) It should be external when you have more than 1 server running the
> same application (so they can share cache?)
>
> c) no idea on this one. ;)

My opinion is close to yours on most points:
a) where it makes sense (speed things up, data that can spare being 59 minutes
old...)

b) I guess external makes sense since we keep having 2 production instances, but
I'll have to figure out how to configure it properly then

c) No idea either :)

Pierre