Rob Evans (robevans) wrote:
Folks,
I'm evaluating Avalon Merlin for use in a project and need some guidance
in regards to hot deployment.
SCENARIO
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Developers require the ability to deploy new components into a running
container as well as upgrade running components.
QUESTION
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Does Avalon Merlin support this out of the box?
1. in principal - yes 2. in practice its not been validated 3. its not trivial
If not, is it feasibleYes - what you have available is a complete meta-model that describes the deployment scenario for components and containers. You can programmatically manage deployment and containment descriptors and fiddle with things like changing configurations, context values, even classloader information. What is not yet in place is event model to notify a runtime controller (Appliance or Block) of the changes. With such event model in place the controller has to take the appropriate action - for example - a change to the classloader would imply demounting components in the classloader - which implies suspension of consumers (or at least disabling service provision), redeployment of a container and its components, from which life continues as normal. The principal is that this can occur at an isolated point within a containment hierarchy - as such you can view these change as runtime micro-adjustments to the deployment solution.
to implement this ourselves?
If you do this yourself your will be totally inside the composition and activation packages. You may want to take a first step of programmatic deployment - just playing around with the deployment meta-model, appliance and block classes and getting familiar with the internal architecture.
Cheers, Stephen.
Thanks in advance for your time.
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Stephen J. McConnell mailto:[EMAIL PROTECTED]
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