Manju wrote:
> 1. First thing is, Why do we need phoenix? I agree that it makes use of
> few other subprojects(Excalibur, logkit, framework) which might be of 
> some help, but still, what are the advantages of using phoenix. How 
> helpful will it be for my application(any)

  For the developer Phoenix provides a ready-to-run service activation
  and execution framework.  At the simplest level this means that there 
  is a "root" component manager ready, willing and able to handle child
  components that you add. Developers will also find that using Phoenix 
  enforces structure that is too-easily overlooking in many 
  environments.  You end up being much more rigorous about separating 
  out independent service units (blocks) and making these units 
  reusable and deployable in a consistent manner.

  For the person dealing with several services Phoenix presents another
  set of advantages.  The application OSM is building currently has 20
  separate top-level blocks (and that number is growing reasonably 
  steadily).  Within Phoenix these blocks must declare the services
  that provide and the services that they are dependent on.  Phoenix
  provides the mechanisms for composition of these services without
  being forced to delve into source code.  It also provides the 
  runtime support for ordered activation of services taking account 
  multiple dependencies.

> 2. Should all the applications under apps directory be web based atleast
> a server based application which listens to some port?

  It academic - a service could be a "server", "peer", or just a 
  black-box figuring out the meaning of life.  What is more important
  is the relationships between these services and the ability to 
  seperate service development from service management.

> 3. Can one application talk to another application talk to another
> application under the apps directory(i know this should be possible)?

  In our environment with have this requirement at three levels. The
  simplest case is a child component that needs to talk to a parent 
  container and this is readily handled using the Avalon framework 
  contracts concerning composition and contextualization (in effect 
  you the container provides the child component the resource it 
  needs which could include callback references etc.).  The second 
  case concerns mutual dependencies between blocks (e.g. UserBlock
  needs TaskBlock, but TaskBlock needs UserBlock). We have typically
  resolved this be declaring a single dependency (e.g TaskBlock 
  depends on UserBlock) then invoking a callback in the dependent 
  notify the provider of its availability.  The third inter-block
  object to mechanism concerns cross-Phoenix communication.  In those 
  cases you have available all of the classic cross-VM communication 
  mechanisms (we use CORBA for our systems because of the ability
  to separate invocation from service context, language independence,
  etc).

> 4  Can i have more than one webserver/servlet engine under the apps
> directory? For example there is something called avalon-bay from 
> cornerstone which uses tomcat.

  In my opinion the avalon-bay stuff in cornerstone should either 
  be substantially upgraded or dropped.  In its current for it does 
  not build with the latest version of Tomcat and after solving that 
  you will still have a lot of work to do to get something running.
  As to the question of "multiple services that do the same thing" ..
  the answer is yes.

>     Will it be OK if i have two or more applications using tomcat or any
> other server for that matter?.

  Sorry, don't understand the question.

> 5. When i execute run.bat from phoenix, how will it identify and start
> the servers under apps directory?
 
  Details about this are included in Pheonix documentation. 
  http://jakarta.apache.org/avalon/phoenix/assemblers-guide.html

> 6. Will i be able to run any webserver, for example, iPlanet, Weblogic,
> websphere,
>     ...over phoenix?

  If you can wrap it inside a block you can run it.

Cheers, Steve.

Stephen J. McConnell, OSM sarl
digital products for a global economy
http://www.osm.net
mailto:[EMAIL PROTECTED]





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