Remote Storage Resource Management in WS-PGRADE/gUSE - Science Gateways for Distributed Computing Infrastructures - page 78

Blacktop. This solution avoids individual user ticket administration, and still
ensures detailed access control.
Use of the Data Avenue Web Services through direct web service calls, or the
Java API provided, respectively, also requires a ticket, called an

“ API ticket ” . This

API ticket can also be requested on Data Avenue ' s web site.

5.5 Conclusions

Numerous storage solutions have been evolved during the past decades; however,
accessing and managing data typically still requires IT expertise, installation, and
learning the related tools. These kinds of skills often cannot be expected from every
user community wishing to exploit the computation power of distributed computing
infrastructures. Also, the requirements of dedicated APIs that make it possible to
access different storage resources often prohibit the deployment of user applica-
tions, or, at least, limit their portability.
Data Avenue offers a flexible and extensible solution for these problems. It
provides an intuitive, web-based graphical user interface, through which users can
easily perform their most common operations on storage resources, and a Blacktop
server, which provides a web service interface to perform operations on remote
storage resources via simple web services. In this way, Data Avenue services are
accessible in various ways from portlet containers to custom applications written in
any programming language.
Data Avenue has also been integrated into the WS-PGRADE/gUSE portal
framework. On one hand, Data Avenue

is user interface is available within the
portal, and on the other hand, workflow execution is extended in a way that jobs can
access remote input

'

files, or upload their outputs. All operations required to manage
remote storage resources are performed by the portal automatically, and are
transparent for the users. Combining this technology with the coarse-grained
interoperability solution of the SHIWA and ER-Flow projects, users can transfer
remote data among different kinds of workflows (Kepler, Taverna, etc.), no matter
in which DCI they are actually executed. Finally, extra care is taken on security
issues that arise in any mediation service when using Data Avenue.