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Date: Sun, 02 Aug 2009 22:37:52 +0100
From: Simon Nash <nash@apache.org>
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Subject: Re: [1.5.1] Domain manager and binding.sca
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Simon Nash wrote:
> When creating a domain configuration from scratch using the
> Domain Manager GUI, the generated configuration files don't include
> a <binding.sca> entry.  This means that deployed composites that
> use binding.sca for inter-node communication don't work "out of the
> box" in a distributed domain configuration.  In order to get this
> to work, it's necessary to manually edit the generated domain
> configuration to add <binding.sca> elements to the node definitions.
> 
> IMO this is a serious usability issue for someone just starting
> with the distributed domain and I would like to change the domain
> manager to generate a <binding.sca> entry in the node configuration.
> This is a simple one-line change and it doesn't cause any problems
> in a full build.
> 
> Adding this entry makes the distributed domain work "out of the box"
> with binding.sca.  However, with the current domain mananger code,
> this change also removes the local optimization for inter-node calls
> using <binding.sca>.  This is because the node configuration algorithm
> is currently "all or nothing" which means that all references and
> services using <binding.sca> would get an http:// absolute URI, forcing
> them to use binding-sca-axis2 for communication rather than binding-sca.
> 
> The correct solution is to make the domain manager URI generation
> algorithm more intelligent and only create the http:// style of
> URI for binding.sca references and services that use inter-node wires,
> not those that use intra-node wires.  Unfortunately this change is
> not simple because URI generation in the domain manager currently
> precedes domain wiring, which means the URI generation code doesn't
> know which references and service are wired together.
> 
> I can see 3 options for 1.5.1:
>  1. Don't add <binding.sca> to node configurations in the domain
>     manager, and force users to do this manually.
>  2. Add <binding.sca> to node configurations in the domain manager,
>     and accept that there won't be any local optimization when
>     binding.sca is used in a distributed domain configuration.
>  3. Add <binding.sca> to node configurations in the domain manager,
>     and also fix the URI generation algorithm to preserve local
>     opimizations where they are applicable.  I am currently thinking
>     about how best to implement this change.
> 
> I am willing to work on option 3, but including this will delay the
> release a little.  I don't think option 1 is acceptable.  I could live
> with option 2, but others might not be happy with this.
> 
> Comments, questions, opinions, preferences?
> 
>   Simon
> 
>
I have an idea for how to make option 3 work with only minor changes
in the builders.  I have written some code and I will test it tomorrow.

   Simon