Enabling Grids for e-Science: The EGEE Project - Grid Computing: Infrastructure, Service, and Applications - page 61

Access

CLI API

Security

Information & monitoring

Authentication

Information &
monitoring

Application
monitoring

Auditing

Authorization

Data management Workload Management

Metadata
catalog

File & replica
catalog

Job
provenance

Package
manager

Accounting

Storage
element

Data
movement

Computing
element

Workload
management

FIGURE 3.3 gLite components.

as user job-related information. The information system is based on
hierarchical LDAP servers.
Job management services allow the execution and management of jobs,
in particular the computing element provides an abstraction of the physi-
cal computing resources and the workload management services is a
metascheduler dispatching jobs to appropriate computing elements. A
basic package manager allows VOs to install VO-specii c software at
different sites. The job provenance prototype allows the long-term storage
of job-related information and thus the replay of full workl ows. Access to
compute resources is provided via Condor and GT2 GRAM (which is cur-
rently being updated to GT4 GRAM), and work on an HPC-Proi le/BES [17]
-compliant interface is ongoing [18].
Data services allow the manipulation of and access to data and i les. The
storage element provides an abstraction from the underlying physical
storage location, the i le and replica catalogue allows managing the logical
namespace and locating i les on the infrastructure, and the data man-
agement components allow managed transfers of data and provide data
management workl ows like creating and deleting replicas of i les. EGEE
has standardized on the SRM [19] interface to storage resources, for which
a number of production-level implementations are available. GridFTP is
used as underlying protocol for data transfers.