UK National Grid Service - Grid Computing: Infrastructure, Service, and Applications - page 156

actually used. The purpose of this service is to enable users to monitor if
they are approaching their allocated limit of CPU time and to allow them
time to reapply for more hours if required.
6.7.2.5 BDII MDS Service
The support center runs a Monitoring and Discovery Service (MDS) for
the National Grid Service using Berkley Database Information Index
(BDII) from the EGEE project. It retrieves data from NGS sites by querying
the Grid Resource Information Service (GRIS) at each site and makes it
available via an LDAP server. The information is primarily for the auto-
matic discovery of resources by a resource broker, but can be viewed on
the NGS Web site it may be queried on the command line if an OpenLDAP
client is installed. The BDII server reports its availability every 15 minutes.
If a failure is detected during normal working hours, then a system admini-
strator is contacted in order to investigate and resolve the situation.
6.7.2.6 Advanced Reservation
The support center hosts an advanced reservation form on the NGS Web
site, for users to request resource reservation in the case of, for example,
training and demonstrations at conferences. The support center manages
the reservation process, coordinating the reservation with the sites as
appropriate.
6.7.2.7 Wiki
The support center provides a Wiki for NGS stakeholders to share infor-
mation. In order to add information to the Wiki, a user needs a recognized
certii cate (such as one provided by the NGS Certii cation Authority). The
purpose of the Wiki is for the NGS community to share information that
may not be contained on the NGS Web site, for example, users sharing
their experiences of how to use certain applications, or explain the pur-
pose of any virtual organizations that they may belong to.
6.7.2.8 Grid Operations Center DB
The Grid Operations Center DB (GOCDB) contains general information
about participating Large Hadron Collider Computing Grid (LCG) sites,
their various computing resources (nodes), any periods of scheduled
maintenance, and their site administrators and other contacts. The data-
base can be accessed by users holding X.509 digital certii cates. Any user
certii cate generated by an LCG-recognized CA will work. The support
center is responsible for ensuring that relevant NGS data are published to
the GOCDB.