There is a large distinction between Component-Oriented-Programming and Service-Oriented-Programming. Confer:
http://avalon.apache.org/developing/introduction.html http://avalon.apache.org/framework/guide-cop-what-is.html My take on it is that components are conceptually-extended objects, mainly replaceable at runtime, while services simply provide a service and are less flexible. One serious effect is that components are NOT singletons like Services typically are. As a note, EJB's are not guaranteed singletons either, which is the reason for all the Transaction and Resource junk that Bean Containers must provide. An example of where this makes a difference: Our Components had to become Singleton Services because they all use a Clustered Replicated Read/Write Cache that requires each Service to have only 1 instance per JVM. The problem with Components was that we could have a number of cache-members in each JVM (one per component instance), which meant there would be an unnecessary amount of cache-related network traffic and processing overhead. Using singletons guarantees only one cache-member per jvm, which is most efficient inside a clustered system. I Hope this helps, Chris > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Tuesday, June 10, 2003 10:49 AM > To: [EMAIL PROTECTED] > Subject: RE: Avalon and Turbine services... > > > Just my 2 cents... > > Avalon provides a standard way to configure what they call components, and > we call services. This allows Avalonized components from other > areas to be > used with Turbine and vice versus.. > > For example, the Avalon wrapper around Hibernate allows hibernate > to be used > in anything supporting Avalon, which includes Turbine. Additionally, the > Avalon services architecture is much better thought out then the existing > Turbine or Stratum ones... > > I would recommend checking out the code in xingu.sf.net and the avalon > wrapper around hibernate (hibernate.sf.net). Look at that, and how it is > tied into Turbine. In the 2.3 cvs tree is a Turbine/Hibernate Howto... > > Eric Pugh > > -----Original Message----- > From: Rodrigo Reyes [mailto:[EMAIL PROTECTED] > Sent: Tuesday, June 10, 2003 12:03 PM > To: turbine-dev > Subject: Avalon and Turbine services... > > > Hi all > I have been trying to understand the relation between Turbine services > and Avalon, but I am still a bit unclear. Is Turbine trying to migrate its > services to Avalon? Is that what we are calling "avalonization"? > If so, why? > I know the next question is not directly related to Turbine, but > if I get an > answer from you guys here, that could save me from becomming a > member of yet > another mailing list :) Why do we need Avalon? Isn't Avalon doing the same > job an EJB container is supposed to be doing? Or is Avalon providing extra > functionality/services? Sorry if this last question seems dumb to many of > you, but I might not be getting this right yet. > Thanx in advance... > > Rodrigo > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
