I'm not a big fan of broadcasts for lookups. I once worked in an
OS/2 and LAN Server environment, where the network was crippled for
minutes at a time by broadcast storms. I guess we don't want to design
our product around poor network implementations, but... Just please make
sure to cache this information wherever possible to minimize the
broadcasts.
Also, this really can't be the only way - one of the apps I worked
on was a big fat applet that talked directly to an EJB back end, and the
client was most certainly on a different subnet. You can make
broadcasting the *preferred* way, but not the *only* way.
Thanks,
Aaron
On Tue, 10 Oct 2000, Rickard [iso-8859-1] �berg wrote:
> I am planning to update jBoss for clustering shortly. The first part to
> be reimplemented is the JNDI naming system. It will use Jini, and thus
> will have no problem with running several instances for the same
> namespace. This will be one of the central parts of the new clustering
> system.
>
> Basically all JNDI service providers will be registered in a Jini Lookup
> Service, and associated with a cluster name. The client will set the
> PROVIDER_URL to the cluster name (not host/port!) and the client
> implementation of the JNDI provider will then look in Jini for all
> available provides for that cluster. Because of this there is no need
> for the JNDI server to run on a particular port, so there will be no
> clashes between multiple instances on the same machine. It also means
> that clients will not have to know any host names of the cluster nodes,
> just the !cluster name!, which allows for a "zero admin solution"(tm).
> You can add nodes at runtime which simply registers in Jini and become
> available to the client.
>
> The drawback of this solution is that the client and server has to be on
> the same subnet (because Jini uses multicast for lookup). This will not
> be a big problem in most cases since the most common case is to use a
> webserver as client, which almost always is on the same subnet. If
> anyone objects to this assessment, please let me know and I will take
> into account clients on different subnets (Jini can work in this case
> too, but not as dynamic).
>
> /Rickard
>
>
