
and meta-data servers). It receives requests from any
subsystem and knows how to delegate these requests
to the appropriate subsystem for execution; after
execution, the results might be sent back to the
requestor. The Dispatch Server also offers
capabilities of a workflow system to implement
Eurostat Applications. It relies on the Meta-Data
Server for its operations. The associated Job Server
acts as an extension of the Dispatch Server for
queuing, scheduling, handling, managing and
monitoring batch, bulk data transfer or print
requests. As opposed to on-line requests, batch or
print requests may be executed when system
resources are available (in order to use them
efficiently) or at a user-defined moment in time
(scheduled actions).
- The STADIUM Server: This module represents the
encapsulation of an existing environment made by
the Stadium and Statel tools used to receive data sets
from data suppliers, record information about data
issuers and recipients in the EDIFLOW database,
put the datasets in the relevant directories and notify
operational users about the availability of data.
- The CVD Manager: Its role is to deal with
handling data related to the Data Life Cycle (CVD).
It records information in the Meta-Data Database
(via the Meta-Data Server) about the status of the
Eurostat Applications, datasets or statistical meta-
data. The CVD Manager mostly receives its
information from the Stadium Server and the
Dispatch Server assisted by the OSAC and OSDC
Driver Managers.
- The Eurostat Portal: This is a mediating facility
between external users (using a web interface and
looking for Eurostat's public or payable data,
products or services) and the REFEX via the
Dispatch Server. It receives requests from a client
(usually a web browser) and forwards these requests
to the Dispatch Server for further processing by the
relevant back-office service. It has to combine
reliability, performance and security with the ability
to deliver dynamic, personalised content, in an easy-
to-manage environment enabling worry-free
deployment of web-sites. Personalisation of services
offered to customers (or profiling) can be envisaged.
Internal users can use the portal as well to access
Eurostat’s data, services or applications.
Application System
The Application System environment is made of
Eurostat Applications, i.e. statistical production
systems, and a number of functional servers, called
Thematic and Support Application Servers. Access
to these servers is provided via the OSAC (Open
Statistical Application Connectivity) Driver
Manager.
- Eurostat Applications: These are the data
processing and manipulation systems in use in the
various production units of Eurostat to produce
statistics (e.g. Acier, LFS, Eurofarm, FISH, Forest,
PPP, TRAINS…). They are controlled by
operational users in their day-to-day work. In most
cases, they have been developed and installed by
external contractors according to Eurostat’s
requirements. The trend is to develop these
applications as workflow systems calling services of
the thematic servers.
- Thematic and Support Servers: It is planned to
divide the business logic of applications over a
number of Thematic Servers, each one performing
well-defined tasks. It is the idea to organise
functionalities used at Eurostat into a set of
Thematic Servers based on the Data Life Cycle
activities (e.g. data reception, data validation,
estimation, seasonal adjustment, reporting…). For
instance, all operations/services dealing with the
validation of received data will be put on a
Validation Server. Similarly, all algorithms/methods
for seasonal adjustment will be placed on a Seasonal
Adjustment Server. It may be clear that each
Thematic Server has to offer a clearly defined
interface to other components of the architecture,
and especially to the Dispatch Server which knows
operations only by their name, logical name of the
application server and list of parameters. In fact, it is
the role of the OSAC Driver Manager to hide
specific features of application servers to the rest of
the architecture. The functional operations will be
implemented as remote services accessed in a client-
server mode and will be functionally grouped by
Thematic & Support Application Servers. The
servers used for their implementation may be based
on specific platforms such as Oracle DBMS, Fame
software, SAS software, etc. Support Servers are
servers hosting commercial tools (e.g. Business
Objects, Matlab…).
- OSAC Driver Manager: The aim of the OSAC
Driver Manager is to offer a straightforward
organisation of all predefined functional operations
or support services available at Eurostat and to offer
an easy-to-use and uniform navigation mechanism to
locate these functional operations (by means of
DEVELOPING A CORPORATE INFORMATION SYSTEM ARCHITECTURE: THE CASE OF EUROSTAT
25