Metadata

ExternalObject resources support the common CIMI attributes, such as name, description, and property, as well as a bucketName and objectName. These attributes can be used to provide descriptive metadata for the underlying data objects. The standard CIMI filtering mechanisms can then be used to select ExternalObject resources based on that metadata. These limited attributes are sufficient for many use cases.

Some use cases, however, will require a richer set of metadata. SlipStream already provides a resource that allows for rich metadata to be provided for other managed resources–the ServiceOffer. In the same way that ServiceOffers can describe Virtual Machines offers, they can provide metadata for ExternalObjects as well. In this way, the CIMI filtering capabilities can be used with the richer metadata to provide full-featured search of data sets.

As the schema for the ServiceOffer is completely open, all metadata associated with an ExternalObject, both general and domain-specific, can be tied to the underlying data object. The relationship between these resources is shown below.

SlipStream Data Management Resources

Once the ServiceOffer and ExternalObject resources have been registered in the system, users can find data objects of interest by doing the following:

1. Using the standard CIMI search and filtering capabilities to find ServiceOffer resources that describe data objects of interest.
2. Follow the “href” links to ExternalObject resources that provide a proxy for the underlying data object.
3. Request a presigned, read URL from the ExternalObject resources to get direct access to the data via the HTTPS protocol.

This process combines high-level filtering capabilities with efficient, direct access to data.