Creating Gateway Alliances Using WS-PGRADE/gUSE - Science Gateways for Distributed Computing Infrastructures - page 248

limited resources associated with each VM. However, within the STARnet archi-
tecture heavy simulations and computational tasks are performed on the underlying
DCIs, and thus do not affect the overall performance of the STARnet gateways.
The Liferay and gUSE databases, the local gUSE storage, and the local gUSE
application repository are con

gured either on the hosting machine or on a different
server of each site to facilitate regular upgrades of new VMs containing bug xes

and the latest WS-PGRADE/gUSE gateway releases.
The following services are shared among the different science gateways:

Single sign on (SSO) authentication, which allows users to log into the different
gateways using the same credentials.

￿

Workflows/portlets sharing: SHIWA/SCI-BUS repositories store the workflows/
portlets with related metadata, allowing investigation of their interoperability
with other workflow systems and dissemination across different gateway users
and also to external relevant communities through the SHIWA simulation
platform (Chap. 9 ) .

￿

￿ Shared data: A Data-on-a-Cloud infrastructure allows sharing of user data within

an environment that is accessible from each gateway to allow different pro-
cessing through different applications.

The following services are locally preserved:

Local Liferay accounts: these user credentials are typically associated to a
particular gateway.

￿

gUSE local application repository for storing workflows and related metadata
information on the individual gateway.

￿

gUSE storage for storing private user datasets.

￿

To enable shared authentication an SSO Shibboleth (SHIBBOLETH 2014)
service is employed, which allows a wide range of login handlers from LDAP to
X.509 user certi cate login. The Identity Provider is a Java Servlet web application

and user identity information pulled from an LDAP service, and the Liferay
authentication is performed using a Liferay Hook plugin (LIFERAY-SHIBBO-
LETH-PLUGIN 2014).
Shared authentication allows for easier connection of the shared storage to
gateways. Shared storage services are performed using Unison, 1 to allow data

synchronization on a star topology network, and ownCloud, 2 nd

their data in all the STARnet Gateways,while the ownCloud client enables end
users to share

that lets users

files on their desktops or smartphone devices.

1 Unison webpage: www.cis.upenn.edu/

bcpierce/unison .
2 OwnCloud webpage: http://owncloud.org/ .

*