[erlang-questions] MySQL cluster - MnesiaXXL

Pat e <>
Mon Oct 23 19:57:41 CEST 2006


Also for example if we wanted to have Mnesia RAM-only serving (if it
can serve tables on 128GB RAM machine - that will have to be
benchmaked.....!! :) ) - with MySQL backing up data  what would be the
path best threaded - if it's safe to thread that path at all.. :)


Patrick


On 10/23/06, Yariv Sadan <> wrote:
> Hi!
>
> I think memcached is the best cache available _assuming you're not
> using Erlang_, but if you are building an Erlang app, I can't see why
> you would want to use memcachd instead of Mnesia.
>
> - Mnesia runs in the same memory space as Yaws, which means it's insanely fast.
> - Mnesia is a piece of cake to use.
> - Mnesia is easy to reconfigure in runtime.
> - Mnesia simplifies your architecture because you don't need to
> install 3rd party components.
> - Mnesia has a lot of capabilities that memcached doesn't have,
> including disc_copy storage, ACID transactions, etc.
>
> If I were to build an Erlang webapp (which is purely hypothetical :) )
> I wouldn't look past Mnesia. I can't see a reason to think that
> memcached is any better.
>
> Regards,
> Yariv
>
>
> On 10/23/06, Yerl <> wrote:
> >
> >  Hi There!
> >  I disagree too Yariv.
> >  In this case, what just don't use the best cache available: memcached
> >  (http://www.danga.com/memcached/) instead of Mnesia.
> >  memcahched = cache
> > MySQL + memcahched = database + cache = "easy, and everyone need to do it"
> >
> >  cheers
> >  Younès
> >
> >
> >  Yariv Sadan a écrit :
> >  On 10/22/06, Pat e <> wrote:
> >
> >
> >  BTW
> > After all is it wise to gamble (i know all of you will say it isn't :)
> > a site reputation and speed when all Mnesia sh#t blows up into your
> > face... but we need real time, and that is where Mnesia it seems
> > shines!
> > Why real time... well lets say you want AJAX tech implemented for all
> > future 5 million users, with all of them contacting each other RT, and
> > not have single glitch in delivery time and reliability (well
> > something like big phone switch operator), and also have for the ease
> > of use (LOL :) have user data on Mnesia disk tables ;)
> >
> >  I disagree :)
> >
> > I know what you're thinking:
> >
> > MySQL = database
> > Mnesia = database
> > MySQL + Mnesia = 2 databases = SCARY
> >
> > However, this changes greatly when you change your thinking so that
> >
> > Mnesia = cache
> > MySQL + Mnesia = database + cache = "easy, and everyone is doing it"
> >
> > (in fact, I believe I've heard of some popular hack called memcachd, no ? :)
> > )
> >
> > To build your app, all you need besides MySQL is one Mnesia table that
> > holds {Node, UserId} tuples. When user A send tries to send a message
> > to user B, you look up the tuple where UserId == B and then you go
> >
> > Node ! {msg, A, B, Msg}
> >
> > That's it. If you want to render HTML pages that display large amounts
> > of data such as user profiles, etc, you user ErlyDB to write the
> > horriby complex expression
> >
> > user:find_id(17)
> >
> > That's all there is to it.
> >
> > At least, that's my take on the problem (without knowing much about
> > what the problem is) :)
> >
> >
> >
> >
> >
> >  I know I'm boring, and that you talked about it many times, but if you
> > don't try - you don't fly (and if you fly, you can also dive easily
> > :=).
> >
> >  And if you are going to fly, use a plane instead of hacking yourself a
> > pair of wings :)
> >
> > BR
> > Yariv
> > _______________________________________________
> > erlang-questions mailing list
> > 
> > http://www.erlang.org/mailman/listinfo/erlang-questions
> >
> >
> >
> >
> >
>




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