CRIC Information Sources

Introduction

This twiki presents the current list of information sources that core CRIC queries to obtain information from existing resources. These include services like BDII, GOCDB and OIM.

Sites are recommended to choose one of the existing sources to publish information about their resources. If more than two sources are used, CRIC allows to configure which source is the primary one to collect information.

List of CRIC information sources

Note that only static attributes for service discovery for computing and storage resources are covered in this twiki. Other services like Frontier, Squids, perfSONAR, etc will be added in the future.

The set of attributes are aligned with Core CRIC functionality description.

GOCDB

Note that since EGI is planning to move more topology information from BDII to GOCDB for ARGO monitoring, the proposal below needs to be discussed and agreed with EGI to be aligned on the use of GOCDB service endpoints and extension properties.

Scope Tags

Scope Tags with the labels of the LHC VOs, that is, alice, atlas, cms and lhcb are needed to identify which services are provided to each VO. Sites should make sure these tags are properly defined and maintained as they help in managing downtimes and identifying available resources by each experiment.

Services

Existing information in GOCDB for computing and storage services is not enough to gather all the information needed by CRIC. For this reason, the following attributes need to be added using the service endpoints and extension properties.

GOCDB Service Type	GOCDB object	GLUE2 Attributes	Description
ARC-CE CREAM-CE CE	Service Endpoint URL	GLUE2ComputingServiceEndpointURL	The network location (URL) of the endpoint to contact the computing service
	Extension Properties	GLUE2ComputingShareMappingQueue	The name of the queue where jobs related to the share are submitted
		GLUE2ComputingServiceType	Type of a CE according to a namespace-based classification
		GLUE2ComputingEndpointImplementationVersion	Version of the middleware stack implementing the CE
		GLUE2ManagerProductName	The type of the LRMS underlying the CE, e.g. SLURM
		GLUE2ManagerProductVersion	The version of the LRMS underlying the CE
		GLUE2ComputingShareMaxCPUTime	The max cputime in seconds that a job may request/obtain. Please note it is a single core value! Multi-core/parallel job limits could be published with the GLUE2ComputingShareMaxTotalCPUTime
		GLUE2ComputingShareMaxWallTime	The max obtainable wallclock limit in seconds for single-core jobs. Please note it is a single core value! Multi-core/parallel job limits could be published with the GLUE2ComputingShareMaxMultiSlotWallTime
SRM XRootD globus-GRIDFTP globus-GSISSHD	Service Endpoint URL	GLUE2EndpointURL
	Extension Properties	GLUE2EndpointImplementationName GLUE2EndpointInterfaceName GLUE2StorageSharePath

Sites interested in automating the publication of these variables can make use of the writeable API that will be available as of version 5.8 (released in Autumn 2016).

BDII

Note that CRIC is currently querying the top BDII but this can be adapted to query site or resource BDII directly if needed, especially if this helps sites to have a reduced set of services to maintain.

The following GLUE 2 attributes are needed:

GLUE 2 Object	GLUE 2 Attribute
GLUE2ComputingEndpoint	GLUE2EndpointURL GLUE2EndpointImplementationName
GLUE2ComputingShare	GLUE2ComputingShareMappingQueue GLUE2ComputingShareMaxCPUTime GLUE2ComputingShareMaxWallTime
GLUE2ComputingManager	GLUE2ManagerProductName
GLUE2StorageEndpoint	GLUE2EndpointURL GLUE2EndpointImplementationName GLUE2EndpointInterfaceName
GLUE2StorageShare	GLUE2StorageSharePath
GLUE2MappingPolicy	GLUE2PolicyRule

OIM

OIM has a very flexible interface to provide all the necessary attributes via json. Ongoing discussions with OIM experts are taking place to understand how this could be better provided. The twiki will be updated as soon as there is a solution in place.

-- MariaALANDESPRADILLO - 2016-09-09