Difference between revisions of "GOCDB/Release4/Development/ExtensibilityMechanism"
Line 15: | Line 15: | ||
* https://goc.egi.eu/gocdbpi/private/?method=get_service_endpoint&properties=(MPI=*) | * https://goc.egi.eu/gocdbpi/private/?method=get_service_endpoint&properties=(MPI=*) | ||
This query would return all <SERVICE_ENDPOINT> elements that support the 'MPI' property with any value. | This query would return all <SERVICE_ENDPOINT> elements that support the 'MPI' property with any value. | ||
* https://goc.egi.eu/gocdbpi/private/?method=get_service_endpoint&properties=(&(MPI=*)(somekey= | * https://goc.egi.eu/gocdbpi/private/?method=get_service_endpoint&properties=(&(MPI=*)(somekey=valueX)) | ||
This query would return all <SERVICE_ENDPOINT> elements that both support the 'MPI' property with any value and the 'somekey' property with a value of 'valueX'. | This query would return all <SERVICE_ENDPOINT> elements that both support the 'MPI' property with any value and the 'somekey' property with a value of 'valueX'. | ||
Revision as of 13:59, 3 August 2012
<< Back to GOCDB/Documentation_Index
<< Back to GOCDB/Release4/Development
Key-Value Pair Property Bag Extensiblity Mechanism
Introduction
- Original RT request: https://rt.egi.eu/rt/Ticket/Display.html?id=3764
- Simiar to the GLUE2 extensibility mechanim, the core GOCDB entities (NGIs, Sites, Services, ServiceGroups, Endpoints) will be extended so that they can define an optional set of custom key-value pairs.
- In doing this, additional parameters could be supplied to the PI for selecting entities that define a particular set of properties. For example "select all Sites/Services that define the 'MPI=true' property."
- As an extensibility mechanism, we do not intend to impose any restrictions on the values of key-value pairs (other than max value length, e.g. 256 chars and the fact that key names will need to be unique within a single property bag, i.e. defining a key-set). Key-value pair meaninings should be determined as a community folksonomy.
PI Examples
The URL query could be parameterised with a known GET request paramter (e.g. 'properties') with a LDAP syntax query string for the value, eg:
This query would return all <SERVICE_ENDPOINT> elements that support the 'MPI' property with a value of 'True'.
This query would return all <SERVICE_ENDPOINT> elements that support the 'MPI' property with any value.
This query would return all <SERVICE_ENDPOINT> elements that both support the 'MPI' property with any value and the 'somekey' property with a value of 'valueX'.
Note:
- The extent to which the ldap syntax query string would be supported will have to be explored. A simplified version including only exact pattern matches and simple wildcards may cover most use cases.
- The property bags may only be applied to a subset of entities and PI queries.
Sample PI XML Output
<?xml version="1.0" encoding="UTF-8"?>
<results>
<SERVICE_ENDPOINT PRIMARY_KEY="50257G0">
<PRIMARY_KEY>123456G0</PRIMARY_KEY>
<HOSTNAME>some.host.ac.uk</HOSTNAME>
<GOCDB_PORTAL_URL>https://goc.egi.eu/portal/index.php?Page_Type=View_Object&object_id=123456&grid_id=0</GOCDB_PORTAL_URL>
<HOST_OS>SL5</HOST_OS>
<BETA>N</BETA>
<SERVICE_TYPE>SomeComputeService</SERVICE_TYPE>
<CORE></CORE>
<IN_PRODUCTION>Y</IN_PRODUCTION>
<NODE_MONITORED>Y</NODE_MONITORED>
<SITENAME>DGIREF</SITENAME>
<COUNTRY_NAME>Germany</COUNTRY_NAME>
<COUNTRY_CODE>DE</COUNTRY_CODE>
<ROC_NAME>NGI_DE</ROC_NAME>
<ENDPOINT>
<URL>ldap://ce-cms.vinca.rs:2170/mds-vo-name=AEGIS10-VINCA-CMS,o=grid</URL>
<InterfaceName>RIS</InterfaceName>
</ENDPOINT>
<!-- Key-Value Pair Property Bag attached to SERVICE_ENDPOINT entity -->
<Extensions>
<Extension>
<LocalID>1234</LocalID>
<Key>MPI</Key>
<Value>True</Value>
</Extension>
<Extension>
<LocalID>12345</LocalID>
<Key>somekey</Key>
<Value>valueX</Value>
</Extension>
</Extensions>
</SERVICE_ENDPOINT>
</results>
Potential Use Cases
A number of potential use cases have been reported (https://rt.egi.eu/rt/Ticket/Display.html?id=3764), including:
- Specifying service access protocol.
- Defining custom monitoring parameters.
- Defining custom functionality/capability flags supported by a service (this may be related to MPI in EGI requirements, see: https://documents.egi.eu/public/RetrieveFile?docid=1260&version=3&filename=VT-MPI_Report_v3_final.pdf and https://rt.egi.eu/rt/Ticket/Display.html?id=3396).
Issues
There is the potential for proliferation of key-value pairs that should instead be recorded in fields/properties as part of the data model.