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SITools – WGISS, May 2006 2
Objective
■ Laboratories often have their own and specific systems to access data and services maintenance ? Interoperability ?
■ SITools is a Research & Development action which aims at : providing unified access to existing data and services in the laboratories providing a set of software (a toolbox) installed and managed by the laboratories creating distributed and interoperable data centres
■ SITools has been developed to demonstrate the feasibility of such a tool.
SITools – WGISS, May 2006 3
Target concepts
■SITools components must be:
light : easy to install and to maintain by laboratory engineers portable : can run on various platforms generic : ability to cope with any type of data and service modular : easy maintenance and flexible use of already existing components interoperable : ability to interface other distributed services.
SITools – WGISS, May 2006 4
Architecture
■Sitools consists of :
an «open-source » software layer (MySQL/PostgreSQL, Apache, Tomcat)
a set of services (webapps hosted by tomcat) : highly configurable interconnected thanks to webservices accessed by client applications
SITools – WGISS, May 2006 5
Database
■Sitools relies on an existing database the database is seen as a file directory meta-attributes are attached to each data (file), e.g.
date of recording, satellite position during recording
■Sitools only needs to add a few generic tables to this database scheme :
to declare « datasets » mapping the existing tables, with related metadata
to describe the existing tables structure, column by column, and define the attributes which are criteria for data search.
SITools – WGISS, May 2006 6
Catalog service
■The catalog service is a tomcat webapp declares the existing database used by a SITools instance and how to
connect to it (login, password) can reference several databases (hosted by several DBMS)
■A sitools instance can use several catalogs located on different tomcat servers.
SITools – WGISS, May 2006 7
Repository Service
■The repository service is the heart of a SITools instance, configured through XML files manages user rights manages the different catalogues used by the instance declares and manages the added value services related to datasets manage the synonyms
synonyms are used to link attributes of different datasets which have the same meaning but different names
requests are processed on the synonyms which enables to have the same interface to access different attributes
SITools – WGISS, May 2006 8
Order service / User workspace
■The order service : enables users to download selected data to a workspace
■The workspace consists of a Web-DAV repository on the Apache server
may contain the metadata of the data that were downloaded.
SITools – WGISS, May 2006 9
Added value services
■ Independent software, interfacing the system, in order to provide additional functions (graphs drawing, datamining, 3D navigation…)
■ Implemented via a servlet interface to be integrated in Sitools instances
may be considered as plugins may be linked to specific datasets through the repository
■No constraint on AVS architecture (web or batch, Linux, Windows),■Can be dispatched over distant Tomcat servers
SITools – WGISS, May 2006 10
WEB Client application
■ Provides the basic functions of a data centre : data and dataset search (according to criteria on attributes) data order added value service user workspace management
SITools – WGISS, May 2006 11
Site C Description of
servicesSite B
Description of services
Client
Site A Description of services
Connection bus between the
various services
Internet browser
Site ASite A
Client Application(Web Server)
Site ASite A
Repository
Site CSite C
Added-Value Services 2
Site CSite C
User Space
Site ASite A
Added-Value Services 1
Site ASite A
Command Processing
Site BSite B
AVS 3
Site BSite B
Catalog off-line
Site N
Added-Value Services N
Synonyms dictionary
Site ASite A
Catalog
Catalog 1 Catalog 2 Data 1
. . .
Catalog 1 Catalog 2 Data 1
Service 1
Existing
SITools – WGISS, May 2006 12
Conclusion
■You can download SITools fron :
http://vds.cnes.fr/sitools/tech.htm
Thank You!