26 lines
1.7 KiB
Plaintext
26 lines
1.7 KiB
Plaintext
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---+ MessageBrokerService
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A MessageBrokerService is a service distributing messages to other services and pooling their responses. It has a single AccessPoint. A MessageBroker will be used for portals but can also be used in a cascading way to create local networks, e. g. for special interest groups. In this way it serves as a gateway to a complete network of distributed services with (potentially) its own registry of services.
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Making the protocol compliant with MessageBrokers would not be a trivial task,
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and probably other more generic protocols would better support query
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distribution. Such protocols could already exist, but we have not
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investigated with more details.
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Therefore we do not specify a complete protocol for brokers now, but we think they are the generalized form of a ProviderService for which a protocol is being specified.
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---+++++ Suggestions for a Broker Service Protocol
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Based on the ProviderService protocol there are some additional complications:
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* Brokers can be cascading, therefore ...
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* how to adress destinations in the header? Do we need to be able to pass on a message to only a subset of other services somewhere down the line/tree of services?
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* how to avoid vicious circles MessageBrokerService loops in the forwarding of messages?
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---+++++ Current Protocols
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Although the DiGIR protocol has some elements
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especifically related to that service (e.g. "responseWrapper" element
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and multiple destinations), it is not validating all messages
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exchanged between clients and the "portal" engine, and it seems the
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protocol is not officialy supposed to cover these types of messages.
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BioCASE on its turn uses a java API for that purpose.
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