Robert wrote:
>Thanks for the info about Merlin. I'm looking through the docs now and
>will download and play with the demo as well. I'm not using the context
>lifecycle, but I think I could really use the dependencies that you
>mention.
>
Great!
Some things to me careful of!
1. make sure you include new component definitions in your jar maniest
(see execalibu/assembly/demo/src/etc/demo.mf for an example)
2. make sure you include the <component-class>.xinfo file in your jar file
3. make sure you inlcude your jar file in a classpath declaration in
either the kernel or container level (see
excalibur/assembly/src/etc/kenel.xml for examples).
Exception reporting on the above cases needs more user friendly messages
(its in the plan).
>
>One problem I have right now is that if one of my components does not
>configure properly, I have no real way of 'knowing' this from other
>components or the container. I'm using 4 components right now and they
>are all interdependent at some level. In a nutshell what would be nice
>is that if a component does not configure the container/service manager,
>etc would know about and not allow it to be active. This might break a
>few rules and from what I know right now, there is no callback from the
>component to say "I'm not ready/configured".
>
>
Interdependecies between a family components generally means circular
dependecies which will result in a failure. The solution to this is to
handle the components "as a family" where the container knows about the
inter-relationships the the lifecycle sequencing that will work. The
Merlin architecture has this in mind - I want to provide pluggable
containers implementations and pluggable kernels that hide "family"
issues like your describing. Currently the Merlin implemenmtation
supports a DefaultKernel and a DefaultContainer - these assume
non-circulare dependency conditions - however, I also need solutions for
"family"based lifecycle management and as such will be introducting
support for this as soon as the core framework is completed.
One of the nice things about the framework is that the seperation of
kernel and container hierachy allowing for the inclusion of a kernel in
a container. This means that a kernel can container a kernel which
means that a one kernel can act as a resource/facilities publisher to a
parent when the parent is preparing and building another set of
components. I.e. you get to control phasing of sub-sets of component
assembly which is really nice in a complex compoent model.
Cheers, Steve.
>- Robert
>
>
>-----Original Message-----
>From: Stephen McConnell [mailto:[EMAIL PROTECTED]]
>Sent: Wednesday, July 17, 2002 12:17 PM
>To: Avalon Developers List
>Subject: Re: Migrating from ECM
>
>
>
>Robert wrote:
>
>
>
>>I have been planning on moving our product off of ECM since it isn't
>>
>>
>the
>
>
>>preferred container anymore (?), and was wondering which one should I
>>
>>
>go
>
>
>>to. I don't think I need phoenix as the container needs to lightweight
>>enough to run in a single, fat-client environment, so I think either
>>Fortress or Merlin would be my choices. So, with that in mind:
>>
>>- Which one is closer to production ready
>>
>>
>>
>
>Merlin is under active development - but its already running compoenents
>
>really nicely, providing:
>
> (a) the component is thred-safe
> (b) the component does not declare a context dependecy (that still
>in progress)
> (c) the component does not declare a default configfuration (that's
>also in progess)
>
>My guess is that the real question concerns point (a) because ECM
>compoents don;t know about default configuration or dependecies. The
>excalibur/assembly package contains several example compoents with
>Merlin doing the automated dependency resolution and lifecycle
>management - take a look at the demo and see if this fits with your
>needs. After a couple of other priority items I would like to focus on
>Fortress/ECM style handler integration for pooled components but thats
>at least three bullet points down the list.
>
>
>
>>- I need configuration as easy as, or close to as easy, as ECM was
>>
>>
>>
>
>I'm confident you will find Merlin configuration easier than enything
>else in Avalon.
>
>
>
>>- I am currently using the connection pooling from Excalibur and would
>>like to continue using it.
>>
>>Any thoughts?
>>
>>
>>
>>
>
>If you want to trial Merlin 2.0 (excalibur/assembly) post me an emil
>off-line and I'll try to help you with the job of getting things
>running. In the meantime, the javadoc for Merlin 2 is really solid - it
>
>will giove you a reasonably good picture of what is possible today and
>what is in the pipeline.
>
>Cheers, Steve.
>
>
>
>>Thanks,
>>Robert
>>-
>>
>>
>>--
>>To unsubscribe, e-mail:
>>
>>
><mailto:[EMAIL PROTECTED]>
>
>
>>For additional commands, e-mail:
>>
>>
><mailto:[EMAIL PROTECTED]>
>
>
>>
>>
>>
>>
>
>
>
--
Stephen J. McConnell
OSM SARL
digital products for a global economy
mailto:[EMAIL PROTECTED]
http://www.osm.net
--
To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
