Hi Freeman,0
Ok in IAS, fault-tolerance is done on the object reference.
Clustering/Fault tolerance.
For example I place the home object "CustomerHome" inside the /refs context
of JNDI. In Inprise IAS, I can place many references of the same name,
under the same name. So I may have /refs/CustomerHome that points to machine
X, and another /refs/CustomerHome that points to machine Y. The naming
service will dish out the references in, for example, a Round Robin fashion.
Replication
I can then configure this naming service to be a master, or a slave (backup)
and to persist its memory in a "pluggable" backing store - which can be a
replicated database.
So from the clients perspective it doesnt know, care, see etc. Which JNDI
service it talks to. It just sets the JNDI properties to the Inprise Context
factory etc. and then underneath it will bootstrap to the naming service and
grab the reference from JNDI (not knowing which JNDI service it got it from)
So now the Naming Service itself is fault-tolerant and persisted, and the
references inside it can be fault tolerant and clustered.This naming
service, and the above explained Clustering/Fault tolerance is also given to
CORBA citizens.
hope this helps,
-Robert
----- Original Message -----
From: Freeman Jackson <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, June 19, 2000 12:57 PM
Subject: Re: replicated name services?
> Rob Castaneda wrote:
>
> > Hi,
> >
> > >> Name Binding is not enough. You need to distribute EJB Home Object
across
> > the >>network too!
> >
> > Give me an example when this is not enough, and why I would have to
> > redistribute the Home object?
>
> You have to distribute before you redistribute. EJB clients need to gain
access
> to the Home object and whatever JNDI limitations you impose on your
application
> will limit your scalability. Maybe you don't need to distribute and
redistribute
> Home objects in a network. The real question is whether or not this is
true.
> Maybe you can give me an example.
>
> > JNDI is a naming and directory service, some
> > containers support dynamic class loading but this has nothing to do with
> > JNDI and obtaining references.
>
> It's not an issue of dynamic class loading but distribution over a
network. EJB
> Clients and Servers on different machines.
>
> > What if my client is a C++ CORBA client
> > accessing through the naming services' CORBA interface.
>
> COSName is ok for certain things but Jini surrogates with COSName a re
possible
> too. It's very easy to write an IDL file and use COSName Stringified
> representations of objects but you still need to distribute/proxy the
object
> somehow over the network.
>
> > Why does it need to
> > distribute the EJB Home object across the network??
>
> Maybe not. Maybe all of your EJB clients and servers run on the same
machine.
> I'm not clear on this point either. .
>
> Freeman Jackson
> EJB Portal Management with Jini Connection Technology
> Siliware, Inc.
> Jini-JNDI Implementation: http://www.siliware.com/jinijndi.zip
> Draft: http://www.siliware.com/whatisnds.htm
> Draft: http://www.siliware.com/techsnds.htm
> Home Page: http://www.siliware.com
> Voice 201-239-0253
>
>
===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the
body
> of the message "signoff EJB-INTEREST". For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
>
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
