Geospatial Systems Architecture Todd Bacastow
GIS Evolution http://wiki.gis.com/wiki/images/8/81/FallSDS11Fig2-1_Evolution.jpg
GIS Users Internet Viewer Component Hand-held Desktop Professional Number of Users Internet Viewer Component Hand-held Desktop Professional Functionality
Market Forces Integrating spatial data analysis and map visualization into key business applications Moving and consolidating spatial data Moving client/server mapping applications to the web and looking to web services
What is an architecture? There is no universally agreed definition A system architecture defines the structure and/or behavior of a system Best be thought of as a representation It is also a process because a sequence of steps It can also be a discipline
Analogies Consider a community that maintains an infrastructure for a public service to homes and businesses. This infrastructure might include: Electricity producers Drinking water purification and distribution Sewage treatment Other waste disposal Natural gas distribution Public transport Cable television and telephones Roads and toll ways
Evolution (Information + computation + hardware + communications)
GIS Configuration Alternative: Stand alone Information + computation + hardware + communications
GIS Configuration Alternative: Connected Desktop Information + computation + hardware + communications
GIS Configuration Alternative: Centralized Configuration Alternative Information + computation + hardware + communications
GIS Configuration Alternative: Centralized Configuration Alternative Information + computation + hardware + communications
GIS Configuration Alternative: Federated Information + computation + hardware + communications
GIS Configuration Alternative: Mobile Information + computation + hardware + communications
Internet/Web Browsers Applications Web Server Broker Databases Web Information + computation + hardware + communications
Cloud Architecture Building Blocks GIS Portal Network architecture (Distributed) Loosely Coupled Internet Standards Many GeoServices Many Clients Metadata Servers Open / Interoperable Full GIS capabilities GIS Users Metadata Server Search Catalog and Find Publish GIS Data & Services Document in Catalog Connect and Use Checkout and Use World Wide Web Author, Manage, Serve Geographic Information Collections Author, Manage, Serve Catalogs Information + computation + hardware + communications
How? Consume and expose Web services for: Mapping Metadata Data sharing and distribution Geoprocessing Provide standard services and components for web developer (.Net, “generic XML/SOAP”, or Java API’s)
GIS Services Enterprise Web Server Databases Broker Browsers Web Applications Services Information + computation + hardware + communications
Integration Information + computation + hardware + communications
Another view of architecture Enterprise Information Computational Engineering Technology
System Architecture ISO Reference Model of Open Distributed Processing (RM-ODP) Enterprise Viewpoint: It is directed to the needs of the users of an information system. Information Viewpoint: It focuses on the information content of the enterprise. Computational Viewpoint: It deals with the logical partitioning of the distributed applications independent of any specific distributed environment on which they run. Engineering Viewpoint: It addresses the issues of system support (platform) for distributed applications. Technology Viewpoint: The technology model identifies possible technical artifacts for the engineering mechanisms, computational structures, information structures, and enterprise structures.
Architecture Development . Architecture Development
Steps Defining Architecture Requirements. to enable the system to meet the community’s goals and objectives. Defining a Candidate Architectures. to evolve an architecture gradually. Defining Enterprise Architecture. integrate it into an enterprise architecture model. Defining Reference Architecture. a working example designed and proven for use in by the participants Validating a Reference Architecture.
Timing is everything