> -----Oorspronkelijk bericht-----
> Van: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]Namens [EMAIL PROTECTED]
> Verzonden: maandag 24 juni 2002 10:56
> Aan: [EMAIL PROTECTED]
> Onderwerp: Re: multicasting questions
>
>
> Thanks for the links, they're really helpfull.
>
> I'm interested because I need to run multiple MMBase instances using the
> same cloud (i.e. db tables), so I have to think of how to synchronize
> these instances, e.g. flushing caches when a change occurs.
> If I understand correctly this is done automatically if multicast is
> enabled. Is that true?Also, do I need "mmservers" for this, since
> Multicast does not require the
> MMBase instances to know about each other?
> Rob van Maris
>
Yes mmbase handles this automagicly, using xml messages over multicast,
mmservers are not
needed for this to be able to 'find' the other since multicast doesn't need
that but it is
used by it to keep track of the servers inside the cluster and to signal and
react if one of
them is down. For example if you have 3 in a cluster than you will have 3
mmservers that are active. if one drops out the other 2 don't seee any
updates comming from that server (ping idea) and make that node inactive in
the mmservers builder. This in turn creates a changed object event so one or
multiple servers can react on this for example by talking over some of
its tasks or mailing someone or even restarting the server in question
(robinhood and frair tuck setup (see
http://www.crhc.uiuc.edu/~bjb/ece/robinhood.html)).
Hope this helps,
Daniel Ockeloen.
