Closing the Gap between Cloud Providers and Scientific Users - Cloud Computing with e-Science Applications - page 124

from external sources, and the amount of stored information are part of the
accounting process. The conversion logic between the IaaS provider and the
e-Clouds pricing schema is also included.
6.4.3 e-Clouds Front End
6.4.3.1 For Researchers
Researchers and e-Clouds administrators can access a complete set of ser-
vices via a web user interface. The web portal is the point of entry for users;
it allows them to administer their personal workspace. In particular, reg-
istered users are able to submit and monitor jobs, upload and delete files
and folders, check execution results, and track their periodic use of e-Clouds
resources. The web portal aims to provide a simple tool for the e-Clouds user
by hiding the underlying complexity of cloud administration.
6.4.3.2 For e-Clouds Administrators
The web portal mentioned also includes an administration panel for the
e-Clouds team. Administrative users are able to manage users, stored files,
and security permissions and check the event log to track the overall system
activity. New applications are configured through the web administration
panel by describing their basic characteristics, including inputs, outputs, and
associated restrictions. The administration panel adapts dynamically to the
application description and presents the relevant options to the end user.
6.5 e-Clouds Implementation
Throughout the next sections, the most important implementation details
are presented. They cover each of the architectural decisions mentioned and
include the particular technologies used.
6.5.1 e-Clouds Front End
The e-Clouds front end is designed to hide the underlying complexity of infra-
structure configuration while allowing users to control the most important
aspects of a scientific workload execution. To effectively achieve this, the web
portal was built with the Ruby on Rails framework, which is certainly gain-
ing popularity among developers. Traditional web application functionalities,
including user management, file handling, and visual design, are built on top
of some popular third-party libraries (gems). For example, the administration
panel was developed using the Active Admin gem [32], which allows a fast
buildup of dashboards and control features based on the model definition.