10. Metacat Indexing¶
Metacat v2.1 introduces support for building a SOLR index of Metacat content. While we continue to support the “pathquery” search mechanism, this will be phased out in favor of the more efficient SOLR query interface. Metacat deployments that opt to use the Metacat SOLR index will be able to take advantage of:
Fast search performance
Built-in paging features
Customizable return formats (for advanced admins)
10.1. Indexed Documents and Fields¶
Metacat integrates the existing DataONE index library which includes many common metadata formats out-of-the-box:
EML
FGDC
Dryad*
10.2. Default Indexed Fields¶
For a complete listing of the indexed fields, please see the DataONE documentation.
Metacat also reports on the currently-indexed fields, simply navigate to:
with “solr” as the engine.
10.3. Index Configuration¶
Metacat-index is deployed as a separate web application (metacat-index.war) and should be deployed as a sibling of the Metacat webapp (metacat.war). Deploying metacat-index.war is only required when SOLR support is desired (e.g., for MetacatUI) and can safely be omitted if it will not be utilized for any given Metacat deployment.
During the initial installation/upgrade, an empty index will be initialized in the configured “solr-home” location. Metacat-index will index all the existing Metacat content when the webapp next initializes.
Note: the configured solr-home directory should not exist before configuring Metacat with indexing for the first time, otherwise the blank index will not be created for metacat-index to utilize.
Additional advanced configuration options may be set. The existing default values for these settings (shared between Metacat and Metacat-index) can be viewed in the (non-editable) metacat.properties file. If you wish to override any of these defaults, the new values may be added to the metacat-site.properties file.
For more details on locating these files and changing Metacat’s configurable properties, see Properties Overview).
10.4. Adding Additional Document Types and Fields¶
TBD: Step-by-step guide for adding new documents and indexed fields.
10.5. Querying the Index¶
The SOLR index can be queried using standard SOLR syntax and return options. The DataONE query interface exposes the SOLR query engine.
Please see the SOLR documentation for examples and exhaustive syntax information.
10.6. Access Policy Enforcement¶
Access control is enforced by the index such that only records that are readable by the user performing the query are returned to the user. Any SOLR query submitted will be augmented with access control criteria corresponding to if and how the user is currently authenticated. Both certificate-based (DataONE API) and JSESSIONID-based (Metacat API) authentication are simultaneously supported.
10.7. Regenerating The Index¶
When the SOLR index has been drastically modified, a complete regeneration of the index may be necessary. Please see the example below to re-index all objects or the Metacat Admin API docs:
# curl -X PUT -H “Authorization: Bearer $TOKEN” https://<your-host>/<your-context>/d1/mn/v2/index?all=true
# where $TOKEN is an environment variable containing your indexer token
Example:
curl -X PUT -H "Authorization: Bearer $TOKEN" https://knb.ecoinformatics.org/knb/d1/mn/v2/index?all=true
10.8. Class Design Overview¶
Figure 1. Class design overview.¶