From: buzz lightyear <buzzheavyyear@...>

Date: September 21, 2007 1:25:47 PM GMT+02:00

To: Nuno Carvalho <nunomrc@...>

Subject: RE: escada and jgcs

Hi Nuno

Apologies - my misunderstanding - yes, jxta would simply be another protocol under jGCS.

My problem still exists with the gpl license, though. Unless someone is able to change this to lgpl then I'm stuck.

Incedently, did you have any thoughts re. hibernates second level cache and gorda/escada?

One last thing - I got a failure notice when I tried to email to community@...

Cheers
Nick

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CC: community@...; jop@...
From: nunomrc@...
Subject: Re: escada and jgcs
Date: Fri, 21 Sep 2007 12:15:02 +0200
To: buzzheavyyear@...

Hi Nick,

On Sep 19, 2007, at 11:52 , buzz lightyear wrote:

I have just gone over what I was trying to do in July and realise that it will be much easier to implement any replication with jxta via tcp streams, and then stream over jxta ..... there are so many ways to configure jxta that coming up with an escada framework for jxta might just frustrate many users

I don't know JXTA very well, but I got the impression that it is a communication infrastructure. Escada is more than that, it uses a communication infrastructure (through jGCS) and does database replication using also the GAPI interface on the databases. It contains protocols such as primary-backup and DBSM, recovery, etc. 

I'm not sure what do you want to do, but JXTA and Escada are not comparable.

At the beginning of the week I tried to build derby-g-0.3 and was unable to do it. I followed the instructions and ran into problems via a unix shell - I have posted this issue to your forum and hope that someone might be able to respond.

I just answered that email. Sorry for the delay, we were all traveling for a demo of the GORDA project.

I also tried to build via netbeans which showed further problems of requiring xalan in the the gorda reflection api - xalan, I think, isn't mentioned in the build instructions.

I can build with eclipse... and I do not remember for the need for xalan on the derby implementation of GAPI. xalan is needed by Derby and not by the GORDA patch to implement GAPI (gorda reflection interface). The docs only refer to the things needed by this patch. 

One last thing - is there any possibility that the escada interface might be set as an apache license instead of gnu - I am unable to use gnu, and consequently escada. If just the interface was set as apache then I would be able to do my own implementation.

Are you talking about the jGCS interface or the GAPI interface? 

I do not manage this king of issues, I added José Pereira on Cc to clarify us about that.

Kind regards,

nuno

From: Nuno Carvalho <nunomrc@...>

To: buzz lightyear <buzzheavyyear@...>

CC: alfranio correia <alfranio@...>,José Orlando Pereira <jop@...>

Subject: Re: escada and jgcs

Date: Fri, 6 Jul 2007 13:27:54 +0100

Hi Nick,

On Jul 6, 2007, at 11:34 , buzz lightyear wrote:

I don't know if you/others have investigated Jxta as a possible  jgcs binding - the current code doesn't make it easy for Jxta to be  implemented.

No, not yet.

However, if SocketAddress is somehow embedded in a (for example)  'Member' interface then the Jxta IDs - there are two primary user  types for peer and peergroup - can also be embedded within a Member  interface, as jxta does reference sockets directly.

I'm not sure if you need this.

Since SocketAddress is an abstract class, you can do something like  this:

 public class JxtaPeer extends SocketAddress {

Member id;

 }

The addresses in Spread are Strings and it works perfectly. You can  take a look at the Spread binding (available for download in the SF) to see how we handle this. jGCS is supposed to be as generic as  possible, so we use Java standard interfaces and abstract where possible.

With jGCS you should also be able to reuse native classes of the  toolkit that you want to use for implementing jGCS. For example, the Appia binding does something like this:

public class AppiaMessage extends appia.Message implements  jgcs.Message {

(...)

}

The messages are created and sent directly to the toolkit without any  conversion overhead.

I suspect that I will press ahead soon and modify a local version  of escada/jgcs. Would you be interested in me sending you anything  I do? I would be unable to update and verify the jgroups and other  bindings as I don't know them. However, the abstraction of  SocketAddress into a Member class should make this relatively easy  for all bindings.

Great! You are welcome to send anything that you have. You can also  expect our help on problems and/or questions you may have.

Hope this helps,

--

Nuno Carvalho

University of Lisbon, Portugal

http://lasige.di.fc.ul.pt/~ncarvalho

_________________________________________________________________

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--

Nuno Carvalho

University of Lisbon, Portugal

http://lasige.di.fc.ul.pt/~ncarvalho

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