Developer's Corner Easy Access to Near Real-Time Data Continued from page 37 Web sites or Web services. Using conditional logic capabilities, the script can be directed to restart services using logic provided by an administrator. ServiceMonitor checks Web Service Description Language (WSDL) and URLs to make sure that the site responds when it should. The new version also checks REST endpoints and ArcSDE. Service Monitor can be downloaded from ArcScripts at www.esri. com/arcscripts. Utility Aids Developers and Esri Generate API usage statistics on dependencies, versions, and calls .NET developers who are developing against Esri application programming interfaces (APIs) now have a new utility that will help them gain a better understanding of the Esri libraries and objects. Esri API Evaluator, published with ArcGIS 9.3, gathers information by scanning executable (.exe) or dynamic-link library (.dll) files for specific usage of .NET types released by Esri. It scans ArcGIS .NET code and generates a complete set of API usage statistics that will reveal the DLL dependencies; version information; and the number of calls made to all Esri assemblies, interfaces, and members. There are two main aspects of the utility: the Scanning wizard for defining the scan and the Results Viewer window for visualizing the results. Rules can be defined to include or exclude specific folders from scanning. Automatic upload of results can be specified in the prescan summary screen. The Results Viewer window shows a representation of the scan results and provides a breakdown of the .dll and .exe files that are using Esri APIs. Drilling down into the results provides information on API usage right down to a count of Esri methods that have been called. Results are also available as a zipped XML file. Scan results can be uploaded to a Web service hosted by Esri for further analysis. Evaluating developer utilization of the current APIs will help Esri better understand the needs of its users. The count of method and property calls to Esri APIs, a list of implemented Esri base classes and interfaces, assembly names, and contact details (if supplied) are uploaded to Esri. Esri will use any results from the evaluator to inform the design of future products for GIS developers. Obtain the Esri API Evaluator from ArcScripts at www.esri.com/arcscripts. Microsoft .NET Framework Version 2.0 Redistributable Package is required for this tool. use a native DOS batch scripting, but UNIX command line, Python, or Perl could be used. An additional back-office process employed is on-demand caching of services. See the articles "Strategies for on-demand caching" and "Updating your map caches automatically: The key to caching dynamic data" on the ArcGIS Server Blog at the ArcGIS Server Resource Center (resources.arcgis.com) for more information on this process. ArcGIS developers and users have created tools that perform similar aggregated live feed functions. To implement aggregated live feeds, one should have a good understanding of ArcSDE and command line utilities, experience with ArcGIS Server, knowledge of DOS (or whatever scripting environment will be used), and a thorough understanding of the data that will be aggregated. The sample script snippets in Figure 1 (a shapefile loader in this case) show how the commands are used to aggregate live feeds. The accompanying table lists and describes resources used to implement this methodology. About the Developers Derrick Burke is the technology team lead in Esri's Technical Marketing Department and has worked at Esri for more than eight years. He was initially in Professional Services as a developer. Currently, he works in Technical Marketing creating prototypes using new technology and developing presentations. Paul Dodd is the GIS systems administration team lead in the Technical Marketing Department. He has more than 25 years of experience in the computer industry working with mainframe, mini, and microcomputer systems and software. For more than 11 years at Esri, he has worked with ArcSDE in conjunction with various Oracle and Microsoft database products and, over the years, has developed several popular data-loading and monitoring utilities for ArcSDE. This methodology data is designed to work with previous, current, and future releases of Esri software. This methodology for providing near realtime data is designed to work with previous, current, and future releases of Esri software. The approach developed by Burke and Dodd uses a variety of samples, scripts, batch files, and utilities. Many of these utilities and command line tools are available as native OS executables (either DOS or UNIX based). Aggregated live feeds developed by Esri 300,000 Esri Customers are within your reach. Advertise today! Maximum Exposure. Minimum Investment. For Rates and Media Kit, visit www.esri.com/arcuser or e-mail us at ads@esri.com. 38 ArcUser Spring 2009 www.esri.com