GIS Software Technology 30th Edition (Fall 2011)

Fall 2011 GIS Software Technology 30th Edition

Since the early 1970s, Esri has continued to develop evolving GIS software technology supporting functional requirements identified by the GIS user community. Sensitivity to software development trends and enterprise architecture strategies provide guidelines for development investment. Esri software developers leverage the latest computer hardware and software technology to maintain leadership in the GIS marketplace. Resources are aligned to provide the best software and services based on GIS customer needs.

This section provides an overview of the Esri software and associated product technologies. Understanding the primary role of each member of the software family will help users identify technology needs and develop a road map for migration to successful enterprise GIS operations.

GIS Software Evolution
Figure 2-1 provides an overview of the Esri software history and the associated third-party technologies supporting GIS enterprise operations.



The early ARC/INFO software provided developers and professional GIS users with a rich toolkit for geospatial query and analysis and demonstrated the value of GIS technology. ArcView introduced easy-to-use commercial off-the-shelf (COTS) software that could be used directly by GIS operational users. Map Objects empowered developers with a simple way to integrate GIS in focused business application environments. Terminal servers enabled remote user access to centrally managed GIS desktop applications. ArcIMS Web services introduced a framework for publishing GIS information products to Web browser clients. ArcStorm and ArcSDE introduced better ways to maintain and share GIS data resources.

Hardware performance improvements led to more efficient programming techniques deployed in the late 1990s. ArcGIS Desktop software gave users a simple and powerful application interface for many standard GIS operations. ArcGIS Server and ArcGIS Engine provide GIS developers with rich processing tools and full GIS functionality for custom application development and deployment. Distributed geodatabase management tools and replication services provide better integration and sharing of geospatial data.

Web technology introduced more ways to share data and services, introducing a new services oriented component architecture along with interoperability standards that enable open and adaptive applications developed from multi-vendor component architecture. Google and Microsoft introduced pre-processed (cached) online global basemap imagery providing free access to geographic information products from home and our mobile devices. Online data and services become an important extension of our GIS user experience. Rich internet client technology improves display performance and system scalability optimizing integration of distributed Web services and data sources. Hardware virtualization and cloud computing provide simpler ways to administer and support GIS applications and services.

Software technology migration from scripts to objects to services accelerated technology change while increasing demands on hardware performance and network connectivity. The change in technology impacted business processes in an evolutionary way opening new opportunities for GIS to support enterprise and community operations, helping customers better understand their world and make more informed decisions.

Many Esri customers developed effective enterprise solutions with the Workstation ARC/INFO and ArcView GIS software provided in the 1990s. The current ArcGIS software provides operational capabilities that were not available with the older technology. Most Esri legacy customers have migrated their data and applications to the current ArcGIS object-based geodatabase technology. New customers support enterprise GIS solutions directly with ArcGIS desktop and server software.

CY2009 saw some remarkable gains in performance and scalability of ArcGIS Server software. ArcGIS 9.3.1 introduced a map service description (MSD) document server deployment option that leverages a new graphics rendering engine, new optimize mapping tools, and worldwide access to high quality cached image base maps. ArcGIS Online, new Resource Centers, and a growing number of Esri User Forums expand and connect the GIS user community on a global scale. This was a remarkable year for GIS performance and scalability, with vendor hardware performance gains of over 70 percent and software processing loads reduced by over 50 percent, expanding entry level GIS software performance to over four times the capacity available just one year earlier.

ArcGIS 10 was introduced in summer 2010 providing a major ArcGIS Desktop user experience update. A long list of productivity enhancements and performance improvements make this a very exciting release. ArcGIS 10 also includes a variety of new collaboration opportunities hosted by ArcGIS.com which include online community basemaps, intelligent map sharing (map packages), and a free browser based ArcGIS Explorer web mapping application. ArcGIS 10 also includes fully integrated imagery management and publication tools, including a new Mosaic Dataset and image processing services. Mobile GIS expands to include iphone applications and editing options promoting the concept of crowd computing (GIS data sourcing from public cell phone Web editing tools) and enhanced mobile operations.

GIS Technology Alternatives
Current GIS technology is available to support a rapidly expanding spectrum of GIS user needs. Solutions are supported by Esri products integrated with a variety of vendor technologies. Data storage and data management technologies are growing in importance as organizations continue to develop and maintain larger volumes of GIS data. Individual server storage solutions are being replaced by more adaptive storage area networks (SANs), enhancing the IT's ability to respond to changing data storage needs and providing options for efficiently managing large volumes of data. GIS data sources include file servers, geodatabase servers, imagery, preprocessed cached data sources, and a variety of business database solutions.

Desktop ArcGIS applications can be deployed on local workstation clients or centrally managed Windows Terminal Server farms. ArcGIS Server can be deployed in workgroups, data centers, along with a growing number of Esri and third party server hosting platforms (including Cloud computing environments).

Web services are supported by ArcGIS Server and legacy ArcIMS mapping services to Web browser clients throughout the organization and the community. ArcGIS Desktop applications are able to connect to ArcGIS Server Web products as intelligent browser clients, enabling connection to unlimited data resources through ArcGIS.com as well as organization resources served through a variety of Esri customer portals. Users can access applications from the Internet or through intranet communication channels.

Mobile ArcGIS users can be integrated into central workflow environments to support seamless integrated operations over wireless or remote connected communication. ArcGIS Desktop applications can include Web services as data sources integrated with local geodatabase or file data sources, expanding desktop operations to include available Internet data sources. GIS enterprise architecture is typically supported by a combination of ArcGIS Desktop, ArcGIS Server, and geodatabase software technology. Selecting the right combination of technology will make a big difference in the level of support for user operational needs and business productivity.

GIS Configuration Alternatives
GIS environments commonly begin with single-user workstations at a department level within the organization. Many organizations start with one GIS manager and evolve from a department level to an enterprise operation. This was common through the early 1990s, as many organizations worked to establish digital representation of their spatial data. Once this data is available, organizations expand their GIS operations to support enterprise business needs.

GIS is a very compute-intensive, data-rich, and graphics intensive technology. A typical GIS workflow can generate a remote user desktop display every 6–10 seconds, with the GIS client application providing hundreds of sequential data requests to a shared central data server for each map display. GIS workflows can place high processing demands on central servers and generate a relatively high volume of network traffic. Selecting the right configuration strategy can make a significant impact on user productivity.

Data can be shared between users in a variety of ways. Many organizations today have user workstations connected to local area network (LAN) environments that access shared spatial data on dedicated server platforms. User applications connect to shared data sources to support GIS operations.

Centralized Data Configuration Alternative
The most simple system architecture is supported by a central GIS database. A central database architecture supports one copy of the production database environment, minimizing administrative management requirements and ensuring data integrity.

GIS desktop applications can be supported on user workstations located on the central LAN, each with access to central GIS data sources. Data sources can include GIS file servers, geodatabase servers, imagery data sources, pre-processed map cache, online Web services, and related attribute data sources.

Remote user access to central data sources can be supported by central Windows Terminal Server (WTS) farms, providing low-bandwidth display and control of central application environments.

Centralized application farms minimize administration requirements and simplify application deployment and support throughout the organization. Source data is retained within the central computer facility, improving security and simplifying backup requirements. A variety of Web map services can be consumed by standard browser clients throughout the organization. Web mapping services provide low-bandwidth access to published GIS information products and services.

Centrally hosted computing solutions provide consolidated architectures at a much lower risk and cost than similar distributed environments. For this reason, many organizations are in the process of consolidating their data and server resources. GIS can benefit from consolidation for many of the same reasons experienced by other enterprise business solutions. Centralized GIS architectures are generally easier to deploy, manage, and support than distributed architectures and provide the same user performance and functionality.

Distributed Configuration Alternative
Distributed solutions are supported by replicated copies of the data at remote locations, establishing local processing nodes that must be maintained consistent with the central database environment as shown in figure 2-3. Data consistency is critical in this type of environment, requiring controlled procedures with appropriate commit logic to ensure changes are replicated to the associated data servers.

Distributed database environments will generally increase initial system cost (more hardware and database software requirements) and demand additional ongoing system administration and system maintenance requirements. Distributed solutions are often required to meet specific operational or security requirements. Distributed systems generally increase system complexity and cost and lengthen system deployment timelines.

In most cases, standard database replication solutions do not meet the unique spatial data replication needs. Most GIS users are interested in replicating regional or selected versions of a geodatabase, which is not understood by commercial replication technologies. ArcGIS software functions provide custom geodatabase replication solutions. ArcGIS Server 9.2 provides support for distributed geodatabase replication, providing and optimum solution to satisfy distributed GIS operational needs.

Expanding GIS Technology Trends
GIS software and computer infrastructure technology continue to expand GIS deployment capabilities and introduce new business opportunities. New architecture patterns are emerging that reduce administration complexity, provide more adaptive deployment opportunities, and integrate user workflows throughout the organization and the user community. Distributed geodatabase replication technology integrates a variety of desktop, mobile, and server solutions into an adaptive geospatial communications environment connecting operations across the enterprise and throughout the community.

Figure 2-4 shows a variety of architecture options available for enterprise GIS deployment. The core GIS can be managed within the Enterprise Data Center, hosting a maintenance geodatabase for building and managing a full range of GIS data resources. ArcGIS Desktop clients located on the Local Area Network can have direct access to central data resources. Remote desktop clients can operate with focused operational area data replicas with incremental data updates with the central geodatabase through geodatabase replication services. Remote terminal client access can be provided to ArcGIS Desktop applications hosted on a Citrix Windows Terminal Server farm managed within the data center. Virtual Server technology can be used to reduce server administration complexity, improve deployment adaptability, and better control and manage data center operations.

ArcGIS Server mapping services can be deployed directly from the data center, or geodatabase replication services can be used to provide incremental updates to ArcGIS Server web services maintained within a private or public cloud hosting infrastructure. The Cloud computing infrastructure provides a new adaptive platform environment for managing high capacity map publishing services.



Evolving Architecture Strategies
Organizations are expanding operations to incorporate mobile users as an integral part of their enterprise workflow. Improved availability and capacity of wireless technology support mobile communication connectivity for a growing number of GIS users.

Figure 2-5 provides a simple overview of common ArcGIS deployment alternatives. Traditional department-level GIS client/server operations are looking for ways to improve access and data sharing with other organizations and introducing new emerging federated GIS architecture strategies. Traditional enterprise-level operations are looking for ways to integrate GIS with other centrally managed business operations and introducing new emerging integrated business solutions based on service-oriented architecture strategies.



Federated GIS Technology
Database and Web technology standards provide new opportunities to better manage and support user access to a rapidly growing volume of geospatial data resources. Web services and rich XML communication protocols support efficient data migration between distributed databases and storage locations. Web search engines and standard Web mapping services support integrated geospatial information products published from a common portal environment with data provided from a variety of distributed service locations. Federated architectures identified in figure 2-6 promote better data management, integrating community and national GIS operations. Geodatabase replication services and managed extract transform, and load (ETL) processes support loosely coupled distributed geodatabase environments.



Service-Oriented Architecture
Technology is changing faster each year, and organizations are searching for more effective ways to manage technology change. During the 1990s, there was a shift in programming methods promoted by commercial software acceptance of component architecture standards. Software development migrated from compiled, scripted legacy languages to object-based programming environments. ArcGIS technology is based on common ArcObjects components used to support a broad range of desktop and server software. Developing new applications and functionality in an object-based programming environment is much more powerful than developing in the traditional scripted software languages.

Technology change is again being influenced by general acceptance of standard Web communication protocols and more stable and available network bandwidth connectivity. Software development is taking advantage of Internet communication standards and network connectivity with a new service-oriented enterprise architecture strategy.

The core components supporting a service-oriented architecture (SOA) are presented in figure 2-7. These components include service providers, service consumers, and implementation of a service directory.

Common Web protocols and network connectivity are essential to support this type of architecture. Business functions are encapsulated as Web services that can be consumed by Web clients and desktop applications. The SOA infrastructure connects service consumers with service providers, may be used to communicate with service directories, and may be implemented using a variety of technologies.

Business environments are influenced by the rate of technology change. Change introduces risk contributing to business success or failure. Selecting the right technology investment strategies is critical. Service-oriented architecture deployment strategies reduce business risk through diversification and reduced vendor dependence. Open standards reduce the time and effort involved in developing integrated business systems, providing integrated information products (common operating picture) that support more informed business decisions. Advantages of a service-oriented architecture are highlighted in figure 2-8.

Esri embraced open standards during the 1990s and has actively participated in the Open GIS Consortium and a variety of other standards bodies in an effort to promote open GIS technology. The initial ArcIMS Web services, Geography Network metadata search engines, Geospatial One-Stop, and the EsriPortal Toolkit technology are all examples of service-oriented solutions supporting Esri's current customer implementations. ArcGIS Server is developed from the ground up to support interoperability and data sharing. Figure 2-9 provides a view of how current Esri software supports the evolving SOA enterprise infrastructure.



The SOA framework includes multiple access layers connecting producers and consumers, based on current client/software technology and incorporating Web application and service communication tiers. Consumers connect to producers through a variety of communication paths. This framework supports a presentation tier of viewers with access to available published services, a serving/publishing tier of services, and an authoring tier of professional ArcGIS Desktop users. This framework supports current client/server connections (client applications), Web applications, and Web services—all available today with current technology. Future vendor compliance and maturity of Web interface standards are expected to gradually migrate business applications from tightly coupled proprietary client/server environments to a more loosely coupled service-oriented architecture. The ideal environment would decouple business services and workflows from the underlying software technology providing an adaptive business environment that can effectively manage and take advantage of rapid technology change.

GIS is by nature a service-oriented technology with inherent fundamental characteristics that bring diverse information systems together to support real-world decisions. GIS technology flourishes in a data-rich environment, and ArcGIS technology can help ease the transition from existing "stovepipe" GIS environments. The geodatabase technology provides a spatial framework for establishing and managing integrated business operations.

Understanding SOA and how it enables business process integration and helps control and manage technology change is important. Organizations must build an infrastructure that can effectively take advantage of new technology to stay competitive and productive in today's rapidly changing environment.



Esri Product Family
The Esri product family, illustrated in figure 2-10, includes a mix of software developed to support a full range of GIS user requirements. GIS software is provided for desktop, server, and mobile user operations. Data management solutions are provided for file data sources, geodatabase, and Extensible Markup Language (XML) based formats along with Imagery and pre-processed map cache.

GIS Web services support a variety of managed, hosted, and shared GIS Internet services. Online resource centers, templates, forums, Web map hosting, collaboration, and global map cache all make ArcGIS.com a growing part of enterprise GIS core technology. ArcGIS Server provides technology for publishing GIS services that can be consumed by ArcGIS Desktop, mobile GIS, and standard Web browsers. HTML JavaScript and new Internet Rich Clients (Adobe Flex and Microsoft Silverlight) provide users with high map quality and improved user display performance over the Web. New iPhone applications make GIS analysis an everyday communication experience. Esri Developer Network (EDN) provides a range of technical services to the Esri developer community through a bundled low-cost developer software license.



ArcGIS Desktop Software Solutions
Figure 2-11 provides an overview of the primary ArcGIS Desktop client operations. Potential candidate workflows support standalone Desktop, connected Desktop, and centralized Desktop configurations.

Standalone ArcGIS Desktop workstation
ArcGIS Desktop workflows can operate as a single standalone workstation using a variety of local data sources. Desktop includes a Microsoft SQL Server Express personal geodatabase, which can operate as a synchronized replica version of a central enterprise geodatabase and host up to 4 GB of geospatial vector data (business layers). The ArcGIS Desktop workstation can also access a local File Geodatabase, which can host up to 1 TB of geospatial reference data layers (base map) incrementally updated from a central enterprise geodatabase. ArcGIS Desktop version 10 can checkout cashed map tiles for high performance local operations and leverage selected map display layers in memory cache for high performance display.

Connected ArcGIS Desktop workstation
ArcGIS Desktop user workflows can operate in a connected local area network (LAN). Standard architectures include ArcGIS Desktop workstations connected over a LAN to a central enterprise geodatabase, Web services, Image data sources, and pre-processed map cache. Servers can be hosted on physical of virtual server platforms environments. ArcGIS Desktop can author and manage an imagery Mosaic Dataset, providing a catalog/library or imagery, rasters, and associated metadata available on networked file shares. The Mosaic Dataset enables dynamic mosaicking and on-the-fly processing.

Centralized ArcGIS Desktop server
ArcGIS Desktop user workflows can use terminal clients to access centrally managed ArcGIS Desktop applications. ArcGIS Desktop can be deployed on Windows Terminal Server using Microsoft or Citrix terminal clients (most Esri customers use [Citrix XenServer (server virtualization)] terminal clients for optimum compute and display performance). 

ArcGIS Desktop Capacity Planning Workflow Patterns
ArcGIS Desktop workflow performance targets can be generated from the CPT Calculator tab. ArcGIS Desktop software technology selections include workstation (wkstn) and Windows Terminal Server (WTS Citrix) workflow architecture patterns. All ArcGIS Desktop workflows use an MXD map document. Light, medium light, medium, medium heavy, and heavy display complexity settings provide a full range of potential workflow performance targets. Figure 2-12 shows the ArcGIS Desktop software technology selections available with the CPT Calculator tab. 

Calculator Workflow Nomenclature
The CPT Calculator generates a workflow name that identifies the selected Software Technology and Performance Parameters. Changes in the software performance parameters will change the workflow performance targets based on performance technology baselines and key performance parameters established from Esri benchmark testing. The System Design Strategies Software Performance chapter will provide more information on establishing appropriate workflow performance targets and building high performance GIS applications and services. Figure 2-13 provides an overview of the CPT Calculator workflow nomenclature. 

ArcGIS Desktop Standard Esri Workflows
The most common ArcGIS Desktop workflow patterns are generated from the Calculator tab and listed in the Standard Esri Workflow section of the CPT Workflow tab. The Workflow tab is the performance target lookup table used for Capacity Planning Design. ArcGIS Desktop workflows include light and medium complexity performance targets for both workstation and terminal server architecture patterns. Citrix terminal server workflows include both vector only and raster image display density, a performance factor that impacts terminal client display traffic. Figure 2-14 provides an overview of the ArcGIS Desktop Standard Esri Workflow selections. 

ArcGIS Desktop Performance
The ArcGIS Desktop workflow performance will vary based on complexity and data source. Figure 2-15 provides a Workflow Performance Summary that shows ArcGIS Desktop light and medium complexity workflows for workstation and Windows Terminal Server deployment. Workstation display response times are based on workstation 100 Mbps network interface connections. Windows terminal client connections are based on T-1 (1.5 Mbps) WAN bandwidth. Workflow Performance Summary includes a full range of dynamic data sources available in the CPT Design tab (SDE_DBMS, small and large File GDB, small and large Shape File.



Mobile GIS
Mobile GIS supports a range of mobile systems from lightweight devices to PDAs, laptops, iPhone applications, and Tablet PCs. ArcPad provides focused software for mobile GIS and field-data collections. ArcGIS Mobile provides focused applications for mobile GIS operations. Mobile iPhone applications connect to Web services for a variety of public GIS information products. All ArcGIS Desktop products—ArcReader, ArcView, ArcEditor, and ArcInfo—and custom Desktop applications can be used on high-end mobile systems such as laptops and Tablet PCs. Figure 2-16 provides an overview of the primary connected mobile workflow alternatives.

ArcGIS Desktop Disconnected Operations
The ArcGIS Server Basic license supports distributed geodatabase replication. Geodatabase replication provides loosely connected synchronization services for distributed geodatabase versions maintained in supported database platforms. Web-based disconnected check-in and checkout services are also provided. One way replication provides incremental updates for file geodatabase reference data. Distributed geodatabase replication is discussed later in Data Administration. Geodatabase replication enables standalone ArcGIS Desktop users to operate as loosely connected mobile clients.

ArcPAD Mobile Operations
ArcPAD provides an optimum platform for ad-hoc field data collection. ArcPAD can operate standalone, with occasional connection to Desktop or ArcGIS Server for checkout and data exchange. ArcPAD devices can support advanced GPS/GIS editing mobile data collection workflows.

ArcGIS Mobile
ArcGIS Mobile applications are focused on field tasked planned from the server. Mobile operators inspect, collect, and monitor real time operations in the field. Devices include real time DGPS. ArcGIS Mobile workflows include an ArcGIS Server synchronization service (periodic wireless data exchange communications with Server and enterprise geodatabase)and an ArcGIS Mobile Provisioning service which deploys new project datasets to field devices over wireless communications. ArcGIS Mobile operations are designed for centralized management of mobile field crews.

Mobile GIS Standard Workflows
The most common ArcGIS Mobile workflow patterns are generated from the Calculator tab and listed in the Standard Esri Workflow section of the CPT Workflow tab. ArcGIS Desktop clients can operate as mobile stand alone workstations. ArcGIS Mobile workflows include the ArcGIS Mobile Client, the Mobile Synchronization Service and the Mobile Provisioning Service. Figure 2-17 provides an overview of the ArcGIS Mobile Standard Esri Workflow selections.

The ArcGIS Mobile workflow patterns used for the Standard Esri Workflows are documented in the Workflow Description section using the Calculator nomenclature. The ArcGIS Mobile 10 client workflow uses an MXD Light complexity 100% dynamic vector only 400x300 pixel display. The Mobile Synchronization Service uses a SOAP MXD light complexity 10% Dynamic (limited to exchanging updated features streamed to client over SOAP interchange) with 400x300 Display. Mobile provisioning service downloads 100% of the Dynamic MXD display over a SOAP connection. Figure 2-18 provides the description of the Mobile workflow calculator performance selection.



Mobile Workflow Performance
Figure 2-19 provides a Workflow Performance Summary for the light and medium ArcGIS Desktop stand alone workflows (SDE_DBMS and small File GD data source options) and the ArcGIS Mobile client, synchronization service, and provisioning service performance profiles.



ArcGIS Server Web Operations
Figure 2-20 provides an overview of the primary ArcGIS Server Web client operations. Potential candidate workflows include ArcGIS Desktop, ArcGIS Engine, ArcGIS Explorer, and standard Web browser applications including ADF clients, JavaScript, Adobe Flash and Microsoft Silverlight rich internet clients.



ArcGIS Server Applications and Services
ArcGIS Server can provide Simple Object Access Protocol (SOAP)/XML-based data services (published reference images) and geoprocessing services to ArcGIS Desktop and ArcGIS Engine client applications, provide a 3D globe cached file data source for ArcGIS 3D Analyst and ArcGIS Explorer clients, and host a full range of map view and edit applications for Web HTML browser clients supported by out-of-the box .NET and Java Web map and editor server development kit components. ArcGIS Server also supports a REST API for JavaScript and rich internet application Adobe Flex and Microsoft Silverlight browser based applications. ArcGIS Server also provides including WMS, WCS, WFS and KML OGC standards based services for use with 3rd party geospacial clients.

ArcGIS images services are fully integrated with ArcGIS Desktop and Server with the ArcGIS 10 release. ArcGIS Server can provide image services from a single image catalog data source or with ArcGIS Server image extension license can leverage the Mosaic Dataset for on-the-fly image processing.

ArcIMS Web Mapping
ArcIMS was a popular solution initially deployed in 1997 for delivering dynamic maps and GIS data and services via the Web. For many years it provided a highly scalable framework for GIS Web publishing meeting the needs of corporate intranets and demands of worldwide Internet access. ArcIMS customers are rapidly moving to ArcGIS Server software to leverage the rich functionality available with the new ArcGIS Server software release. ArcGIS 9.3.1 provides a new optimized dynamic map service that outperforms equivalent map services deployed using the ArcIMS Image service. ArcGIS Server with cached map services provide high quality and high performance well beyond what was available with the legacy ArcIMS technology.

Web Mapping Software Technology Patterns
ArcGIS Server provides a variety of Web mapping applications and map service deployment patterns. The CPT Calculator software technology selections include ArcGIS Server Map Viewer and Editor Application Development Framework (ADF) applications, SOAP services, REST services, and WMS services. Optimized map document (MSD) services are available with the ArcGIS 9.3.1. and ArcGIS 10 release. A variety of Software Performance Parameter selections are available for each technology pattern. Figure 2-21 provides an overview of the CPT Calculator ArcGIS Server software technology selections.



Standard Esri Web Mapping Workflows
The most common ArcGIS Server workflow patterns are generated from the Calculator tab and listed in the Standard Esri Workflow section of the CPT Workflow tab. The list includes the more common ArcGIS Server deployment scenarios. There are many deployment scenarios with significant variation in service time and traffic performance targets. Best practice is to use the CPT Calculator to complete a workflow analysis for each use case, and then use the Calculator generated workflow performance targets for your design. Figure 2-22 provides an overview of the pre-generated ArcGIS Server Standard Esri Workflow selections.



Web Mapping Performance
Figure 2-23 provides a Workflow Performance Summary for the most common ArcGIS Server workflow profiles. This is a small sample of the many workflow combinations that can be generated from the CPT Calculator settings. A common WAN (1.5 Mbps) bandwidth connection is used to represent typical Web client display performance. Display traffic is the primary response time performance factor for most ArcGIS Server deployment profiles. Server processing times will impact system capacity and licensing, with less impact on user performance. The default workflows shown here use a 1024x768 map display resolution - display traffic and client response time improves significantly with smaller resolution image services (600x400 pixels is quite common for many Web services).

Developer GIS
EDN is an annual subscription-based program designed to provide developers with comprehensive tools that increase productivity and reduce the cost of GIS development. EDN provides a comprehensive library of developer software, a documentation library, and a collaborative online Web site that offers an easy way to share information.

GIS Web Services: GIS Web services offer a cost-effective way to access up-to-date GIS content and capabilities on demand. With ArcGIS Web Services, data storage, maintenance, and updates are handled by Esri, eliminating the need for users to purchase and maintain the data. Users can access data and GIS capabilities directly using ArcGIS Desktop or use ArcWeb Services to build unique Web-based applications. ArcGIS Online Services provide instant and reliable access to terabytes of data including street maps, live weather and traffic information, extensive demographic data, topographic maps, and high-resolution imagery from an extensive list of world-class data providers.



GIS Software Selection
Selecting the right software and the most effective deployment architecture is very important. ArcGIS technology provides many alternative architecture solutions and a wide variety of software, all designed to support specific user workflow needs.

Figure 2-24 provides an overview of the GIS software technology alternatives. What is the best data source? What user workflows should be supported by GIS desktop applications? What can be supported by cost-effective Web services? What business functions would be best supported by network services? Where will mobile applications improve business operations? Understanding the available technology alternatives and how each will perform and scale within the available user environment can provide the information needed to make the right technology decisions.

GIS Data Source: Operations can be supported on local disk or CD-ROM, shared file servers, geodatabase servers, Imagery, preprocessed map cache, or Web data sources. Cached map services provide the highest performance and scalability. Local data sources support high-performance productivity requirements with minimum network latency. Remote Web services allow connection to a variety of published data sources, with the drawback of potential bandwidth congestion and slow performance. There are other more loosely connected architecture solutions that reduce potential network performance latency and support distributed data integration.

Desktop Applications: The highest level of functionality and productivity is supported with the ArcGIS Desktop applications. Most professional GIS users and GIS power users will be more productive with the ArcGIS Desktop software. These applications can be supported on the user workstation or through terminal access to software executed on central Windows Terminal Server farms. Some of the more powerful ArcGIS Desktop software extensions perform best on the user workstation with a local data source, while most ArcGIS Desktop use workflows that can be supported more efficiently on a terminal server farm. Selecting the appropriate application deployment strategy can have a significant impact on user performance, administrative support, and infrastructure implementations.

Web Services: The ArcIMS and ArcGIS Server technologies provide efficient support for a wide variety of more focused GIS user workflows. Web services also provide a very efficient way to share data to support remote client workflows. ArcIMS provides the most efficient way to publish standard map information products. ArcGIS Server provides enhanced functionality to support more advanced user workflows and services. Web services are a cost-effective way to leverage GIS resources to support users throughout the organization and associated user communities.

Network Services: Intranet applications can access services provided by ArcGIS Server connecting directly through the server object manager. Network services can be used to support a variety of Web and network applications.

Mobile Applications: A growing number of GIS operations are supported by more loosely connected mobile GIS solutions. ArcGIS technology supports continuous workflow operations that include disconnected editing and remote wireless operations. A disconnected architecture solution can significantly reduce infrastructure costs and improve user productivity for some operational workflows. Leveraging mobile services can provide alternative solutions to support a variety of user workflow environments.

Making the right technology choice can make or break your success. Technology is changing fast, and new innovations bring lots of promise. The temptation to select technology based on promise can contribute to a painful implementation and failed expectations. Selecting the right technology at the right time can lead to optimum success. Replacing aging technology is also important, missing the performance and productivity gains delivered with new technology innovation. Figure 2-28 shows a typical product life cycle, which is getting shorter as technology improves more rapidly each year.  The Capacity Planning Calculator provides a framework for modeling software performance and scalability on available hardware and network communication technology. The Calculator models what we understand about GIS technology patterns and key workflow performance parameters, relationships we can validate with well defined test benchmarks and operational experience. For single workflows, the Calculator provides a complete software and hardware solution. For Enterprise Design solutions, the Calculator provides workflow performance targets that can be used in the Enterprise Design. Figure 2-29 provides one more look at the CPT Calculator as we complete our software technology discussion.

Selecting the proper software and architecture deployment strategy can have a significant impact on user workflow performance, system administration, user support, and infrastructure requirements. The following Capacity Planning Demo provides an overview of the Calculator tab.

CPT Video: GIS Software Technology
<br style="clear: both" /> The next chapter will discuss Software Performance, providing a much closer look at the software performance parameters and baseline performance models in the Capacity Planning Calculator.

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GIS Software Technology 29th Edition GIS Software Technology 28th Edition GIS Software Technology 27th Edition

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