How about Hibernate!?!?!?! 

-----Original Message-----
From: Howard Lewis Ship [mailto:[EMAIL PROTECTED] 
Sent: Friday, October 08, 2004 7:32 AM
To: [email protected]; Jian Wu
Subject: Re: database supplied configurations

Why would you need to subclass ModuleDescriptor?  It's a pretty dumb
data-holder; what you need is an implementation of something that
builds the MD from your database data.


On Thu, 7 Oct 2004 17:38:44 -0700, Jian Wu <[EMAIL PROTECTED]> wrote:
> Hi,
> 
> By looking into RegistryBuilder and ModuleDescriptor. it looks like there
> are two approaches to get configuration data from Oracle Database to
> feed into Hivemind:
> 
> 1. If you can get JDBC Connection to the Oracle DB at your runtime,
>     it seems that it is easier to implement a DB ModuleDescriptor to
>     read/write to DB at each method level.
> 
>    The problem with this approach is right now ModuleDescriptor is
>    a final class, you can not extend it with DBModuleDescriptor to
>    feed into RegistryBuilder
> 
> 2. If you store the hivemind.xml in Oracle DB as BLOB/CLOB or XMLType,
>    then, at start-up time, you could download this xml into a  local temp
file
>    and let RegistryBuilder to read it.
> 
>    If RegistryBuilder can overload processModuleResource method to
>    take InputStream or InputStreamReader as parameter, it might be
>    more flexable.
> 
> My 2 cents
> 
> Thanks,
> 
> Jian
> 
> On Thu, 7 Oct 2004 11:39:50 -0400, Stolbikov, Igor
> <[EMAIL PROTECTED]> wrote:
> > Thank you for your rapid reply.
> 
> 
> >
> > There are few important reasons to keep configuration in the database:
> > a) Be able to replicate any changes to configuration across multiple
hosts.
> > File based configurations are just not very good for it.
> >
> > b) Be able to modify some configuration parameters through the
Centralized
> > Administration tools/GUI. Having Admin GUI to talk with database is
straight
> > forward.
> >
> > c) Per say we don't talk to database directly to get configuration. We
use
> > special Central Configuration Server that is responsible for all
> > configuration updates, reads, and services notifications that forces
> > services to restart when configuration change.
> >
> > d) We have to use Central Configuration as we replacing only portion of
> > existing product and some configuration is shared.
> >
> > e) Fault-tolerance requirements. We use Oracle Database and database
> > replication for all configuration data.
> >
> > We consider configuration to be not static, but not dynamic. Something
> > between.
> > Is tcp/ip port for listening service configuration?
> > It is not very dynamic but not fully static. Administrator might want to
> > change it.
> > Another example: if depending from user set up I want to replace one
service
> > implementation to another, is it still configuration?
> > I am not applying that configuration can be changed often. It is still
be
> > very static. Administrator might want to change may be once a day or
once a
> > week.
> >
> > For our product it is very critical questions.
> >
> > That brings me to question, on how I can write custom ModuleDescriptor
that
> > does custom configuration retrieval logic? Do you have any examples of
doing
> > this for another ModuleDescriptor providers?
> > Is custom "Registry" more practical solution vs custom ModuleDescriptor?
> >
> > Thank you very much again for your time.
> >
> > Igor
> >
> >
> >
> >
> > -----Original Message-----
> > From: Howard Lewis Ship [mailto:[EMAIL PROTECTED]
> > Sent: Thursday, October 07, 2004 10:29 AM
> > To: [email protected]
> > Subject: Re: database supplied configurations
> >
> > My thoughts are that HiveMind exists to complement the *static* nature
> > of your application.
> >
> > When you start talkling about bringing in data from a database, that's
> > dynamic.
> >
> > It would be nice to bring in data from such locations, and Knut's
> > recent work would support that. He made it significantly easier to
> > obtain ModuleDescriptors for other locations; XML files on the
> > classpath is now merely the default.
> >
> > Ideally, it would be nice if you could define your database access
> > code inside HiveMind, but that is not practical; the lifecycle of
> > HiveMind services and configurations simply doesn't allow for that.
> >
> > In theory, you could build a "bootstrap" Registry, and have it
> > construct a second "runtime" Registry.
> >
> > On Thu, 7 Oct 2004 10:21:09 -0400, Stolbikov, Igor
> > <[EMAIL PROTECTED]> wrote:
> > >
> > >
> > >
> > > Hi everybody.
> > >
> > >
> > >
> > > I am trying to evaluate HiveMind to use as foundation for redesign
efforts
> > > of one of our products.
> > >
> > > One of the major requirements for it is ability to support multiple
> > database
> > > stored configurations.
> > >
> > >
> > > In this respect I have few questions to the HiveMind developers: Did
you
> > > ever consider supplying services that will feed Configurations from
> > external
> > > sources, like database to extend Configuration Points?
> > >  What were your design decisions in this case? If no, what do you
think
> > will
> > > be the best way to implement such services? How they can be will
plugged
> > > into HiveMind framework? Shall we just write our own Registry service
or
> > you
> > > can suggest more elegant solutions?  Thank you very much.  Igor
> > >
> > >
> > >
> > >
> >
> > --
> > Howard M. Lewis Ship
> > Independent J2EE / Open-Source Java Consultant
> > Creator, Jakarta Tapestry
> > Creator, Jakarta HiveMind
> > http://howardlewisship.com
> >
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> 
> 
> 
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> 


-- 
Howard M. Lewis Ship
Independent J2EE / Open-Source Java Consultant
Creator, Jakarta Tapestry
Creator, Jakarta HiveMind
http://howardlewisship.com

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