On Mon, Jul 6, 2009 at 11:05 AM, Luciano Resende <[email protected]>wrote:

> On Mon, Jul 6, 2009 at 6:48 AM, Douglas Leite<[email protected]> wrote:
> > Here are some updates from my project, (source code at [1]):
> >
> > 1) A new test scenario was developed: primary-backup with N backups. In
> this
> > scenario we have a server-client application, with N nodes on the server
> > side. The first node to join on the server side becomes the primary
> server,
> > and the subsequent ones are the backups. The primary gets a request from
> a
> > client, and sends a reply to the client and a copy of it state to the
> > backups. When the primary fails, the first backup on the queue becomes
> the
> > new server. On the other hand, when a backup fails, the primary simply
> stop
> > to send updates to it.
> >
> > This scenario was implemented using the guardian-model approach.
>
> What is a node here, is this the same concept of a SCA Node ?


I guess so. Actually, each node is implemented as a component.

Take a look at:
http://svn.apache.org/repos/asf/tuscany/sandbox/dougsleite/guardian-model/src/main/resources/primaryNbackups.composite
The nodes are implemented as components whose name are "Participant#".


>
>
> >
> > 2) A new tag was added to the recovery rules XML file:
> > <affected_participants>. It allows specify in which participants the
> > exception will be raised. For example:
> >
> >         <participant match="*.BACKUP">
> >             <throw_exception
> >
> class="org.apache.tuscany.sca.guardian.itests.primaryBackup.common.PrimaryFailedException"
> > target_context="MAIN">
> >                 <affected_participants>FIRST</affected_participants>
> >             </throw_exception>
> >         </participant>
> >
> > With this rule, only the first backup on the backup queue will have a
> > PrimaryFailedException raised in it's MAIN context.
> >
>
> How is this configuration integrated with SCA and the composite file ?


At this moment the two files are separated, and there is a reference on the
composite file to the recovery rule XML file. I am using a property tag to
link the two files:

*    <component name="GuardianGroup">
        <implementation.java
class="org.apache.tuscany.sca.guardian.GuardianGroupImpl"/>
        <property
name="recovery_rules">src/main/resources/recoveryrules_nbackpus.xml</property>
    </component> *

I do not know if it is the best design, but as a first design I think it is
good. :)


>
>
> >
> > Thoughts?
> >
>
> What are your plans to integrate this into the SCA Runtime ? It would
> be really good to continue the design discussions we had earlier and
> advance on the SCA/Tuscany Runtime integration discussion. I wouldn't
> like to see this as a sandbox side project for much more time.
>
> >
> > [1]
> >
> http://svn.apache.org/repos/asf/tuscany/sandbox/dougsleite/guardian-model/
> >
> > --
> > Douglas Siqueira Leite
> > Graduate student at University of Campinas (Unicamp), Brazil
> >
> >
>
>
>
> --
> Luciano Resende
> Apache Tuscany, Apache PhotArk
> http://people.apache.org/~lresende <http://people.apache.org/%7Elresende>
> http://lresende.blogspot.com/
>



-- 
Douglas Siqueira Leite
Graduate student at University of Campinas (Unicamp), Brazil

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