IDS Metadata Broker Communication

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Message Flows for Connector to Metadata Broker Communication

• Publication of an exemplary Broker self-description document,

• Registering, Unregistering and Updating a Connector at the Broker,

• Querying the content of the Broker, i.e., the registered self-description documents.

• Full-text, faceted Search on registered Broker self-descriptions (optional).

Figure 1: Interaction sequences with a Metadata Broker

Publication

The Metadata Broker, as any other IDS Connector, publishes a Self-Description that can be requested by Connectors:

Implementations:

List of Implementations
IDS-REST
idscp2
multipart

Registering

Both IDS Connector and IDS Resource Self-Descriptions can be registered at the Metadata Broker. Note that a Metadata Broker must only accept Connector Self-Descriptions if the described Connector is identical with the sender Connector.

Implementations:

List of Implementations
IDS-REST (for IDS Connectors)
IDS-REST (for IDS Resources)
idscp2
multipart

Update

Previously registered Self-Descriptions can be updated at the Metadata Broker. Note that a PUT semantics is used as the default mechanism for updates. This means, that the old Self-Descriptions are completely overwritten by the newly received ones. Similar to registrations, usually Connectors can only update their own Self-Descriptions.

Implementations:

List of Implementations
IDS-REST (for IDS Connectors)
IDS-REST (for IDS Resources)
idscp2
multipart

Unregistering

Previously registered Self-Descriptions can be unregistered at the Metadata Broker.

Implementations:

List of Implementations
IDS-REST (for IDS Connectors)
IDS-REST (for IDS Resources)
idscp2
multipart

Querying

The Metadata Broker provides at least one query endpoint, which is able to handle complex, express queries. The query language of the IDS is SPARQL.

Implementations:

List of Implementations	Comment
IDS-REST	The IDS REST Binding does not provide any complex query mechanisms. Instead, it expects that the Client Connector traverse through the offered Web Resources using a series of single requests. See the other Protocol Bindings for query capabilities.
idscp2
multipart

Search

A Metadata Broker allows the search through a frontend UI, providing at least full-text and facet search capabilities for human users.

Implementations:

Comment
Full-text, facet, and other kinds of UI-based search is not intended via IDS protocols and therefore appears only on the frontend. The IDS does not make any specifications how such features must be implemented.

Figure 2: Exemplary sequence of interactions with a Metadata Broker