Re: Entries, ServiceTemplates, and JavaSpaces

Jeff Ramsdale wrote:
> We have an application that used to make direct RMI calls from a
> client to a service. Now we'd like to instead distribute our work
> using JavaSpaces. Previously we were using a ServiceTemplate to find
> appropriate agents and agents were registering their capabilities with
> a user-configurable set of properties (from a properties file) that
> were turned into entries.
>

What prompted the thoughts of changing to a JavaSpace?  This could be
important to solving the problem the "right" way....

> With JavaSpaces it seems we lose the ability to register for
> notification via a ServiceTemplate, and instead must offer a single
> Entry instance with a pre-defined set of fields. First question then:
> does my grasp of the situation seem correct? Second: Is there no way
> at runtime to configure an Entry with dynamic properties?
>

Yes,  you're correct.

Can't think of a way to do the dynamic properties thing - were you
matching on a subset of an Agent's Entry attributes or all attributes?

> Alternatively the agents can register for notification of a generic
> Entry's appearance at which point they can check a Map on the Entry
> for matching criteria. I'm sure this has been done? Sounds like a bit
> of a pain, though, to implement one's own matching criteria--is there
> something already written to do this and is this the recommended way
> to do what we're trying to do?
>

I can think of a few possibilties but I'd prefer not to waste your time
with them until I know a bit more about why you want to do this.

Happy Easter,

Dan.

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