1. Using a LDAP Directory Server for Environmental Data Discovery Donald Denbo NOAA-PMEL/UW-JISAO Presented by Eugene Burger NOAA-PMEL/UW-JISAO http://www.epic.noaa.gov/cdp

2. January 15, 2002 18th AMS International Conference on IIPS2 Objective Develop a data discovery service that enables users to find data sets available from on-line Data Servers based on geographic region, observed quantities, or keyword.

3. January 15, 2002 18th AMS International Conference on IIPS3 Design Goals  Expandable, extensible, and scalable  Use standards when possible (LDAPv3)  Platform independent  Automated population of directory directly from data servers  Tools to aid in the creation of queries  Work both with applications and web servers

4. January 15, 2002 18th AMS International Conference on IIPS4 Approach Extend existing LDAP objects and parameters to create DataServer and DataCollection objects. Develop application to retrieve metadata from Data Server and XML configuration file then merge/update directory entries. Enhance Web Server and Desktop Application to directly access LDAP Directory Server. Develop monitor application to continuously test availability of Data Server and its data collections and appropriately modify directory entry.

5. January 15, 2002 18th AMS International Conference on IIPS5 Architecture Directory service has three major components.  Directory server and the flow of information  The schema (relationship between directory objects and parameters)  LDAP query construction

6. January 15, 2002 18th AMS International Conference on IIPS6 Directory Server  Directory information updated directly from remote data servers.  Queries can be made from both desktop client and Web client. Queries follow the LDAP protocol.  Data server and data collection information can be easily updated. Only Directory Server address needs to be hard-coded into client.

7. Directory Server Web Server Create and Update Entries Data Server Monitor Update Availability Status Directory Search Test Availability of Data Server Data Desktop Client Web Client Data Data Servers

8. January 15, 2002 18th AMS International Conference on IIPS8 Directory Schema  Directory information is structured as a “tree”.  “dataserver” object contains data server location, name, owner, etc.  “datacollection” object contains data collection name, description, temporal and spatial ranges, keywords, owner, etc.

9. o=cdp.noaa.gov ou=Peopleou=Groupsou=CDPServers ou=NODCServerou=TAOServerou=UHSLServerou=EPICCTDServer cid=MonthlySL cid=DailySL cid=HourlySL cid=SouthPacific cid=Alaska cid=NorthPacific Directory Schema

10. January 15, 2002 18th AMS International Conference on IIPS10 Query Construction  LDAP queries have a “Reverse Polish” flavor. For example, &(keyword=atlantic)(keyword=salinity) is requesting a keyword match of atlantic and salinity.  JavaCC parser developed to translate user friendly entry to LDAP query. For example, Temperature AND salinity AND (pacific OR atlantic) is translated to &(|(keyword=atlantic)(keyword=pacific))(&(keyword=salinity) (keyword=temperature))

11. January 15, 2002 18th AMS International Conference on IIPS11 Graphical Query Entry

12. January 15, 2002 18th AMS International Conference on IIPS12 Keyword List  Keyword list downloaded from directory server  Popup used to aid the user in constructing a query

13. January 15, 2002 18th AMS International Conference on IIPS13 Future Directions  Add directory-side parsing and comparisons of date-range strings.  Add directory-side parsing and intersection checking of Latitude-Longitude domain bounds.