Survey Action Service¶
An survey action service is a component that performs analysis of the contents of a digital resource on request. The aim of the survey action service is to enable a detailed picture of the properties of a resource to be built up.
Each time a survey action service runs, it creates a new survey report linked off of the digital resource's Asset metadata element that records the results of the analysis.
Each time an survey action service runs to analyse a digital resource, a new survey report is created and attached to the resource's asset. If the survey action service is run regularly, it is possible to track how the contents are changing over time.
The survey report contains one or more sets of related properties that the survey action service has discovered about the resource, its metadata, structure and/or content. These are stored in a set of annotations linked off of the survey report.
An survey action service is designed to run at regular intervals to gather a detailed perspective on the contents of the digital resource and how they are changing over time. Each time it runs, it is given access to the results of previously run survey-action services, along with a review of these findings made by individuals responsible for the digital resource (such as stewards, owners, custodians).
Operation of an survey action service
- Each time a survey action service runs, Egeria creates a survey report to describe the status and results of the survey action service's execution. The survey action service is passed a survey context that provides access to metadata.
- The survey context is able to supply metadata about the asset and create a connector to the digital resource using the connection information linked to the asset. The survey action service uses the connector to access the digital resource's contents in order to perform the analysis.
- The survey action service creates annotations to record the results of its analysis. It adds them to the survey context which stores them in open metadata attached to the survey report.
- The annotations can be reviewed and commented on through an external stewardship process. This means choices from, for example, a list of potential options proposed by the survey action services, can be verified and the best one selected by an individual expert. The resulting choices are added to annotation reviews attached to the appropriate annotations.
- The next time the survey action service runs, a new survey report is created to link new attachments.
- The survey context provides access to the existing attachments for that asset along with any annotation reviews. The survey action services is able to link its new annotations to the existing annotations as an annotation extension. This means that the stewards can see the history associated with the new information.
Runtime for an survey action service
Survey action services are packaged into Survey Action Engines that run in the Survey Action OMES hosted in an Engine Host.
The metadata repository interface for metadata discovery tools is implemented by the Asset Owner OMAS that runs in a Metadata Access Server.
A survey action service may be triggered via an Engine Action, a governance action type or as part of a governance action process.
Survey Action Pipeline¶
There is a lot of common functions that are used repeatedly during the discovery process.
An open discovery pipeline is a specialized implementation of an open discovery service that runs a set of open discovery services against a single digital resource. The implementation of the open discovery pipeline determines the order that these open discovery services are run.
Each open discovery service in the pipeline is able to access the results of the open discovery services that have run before it through the discovery context. The combined results of the open discovery pipeline are grouped into a single discovery analysis report linked off of the asset.
The aim of the open discovery pipeline is to enable reusable open discovery service implementations to be choreographed together for different types of digital resource.
Further information
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