GALEXView Demo T. Rogers, B. Shiao, P. Brown, P. McCauley, A. Conti, M. Smith, S. Tseng, A. Volpicelli StSci/MAST

GALEX (Galexy Explorer) Mission GALEX launched on launched on April 28, GALEX is an all sky survey in the UV in two bands: FUV and NUV. GALEX Archive Stats: –Over a 100 million source objects –Over 31,000 Image ‘Tiles’ –Database Size: 1.2 TB –Product Files Size: 16 TB

Background Existing Web site (galex.stsci.edu) developed by A. Conti, A. Volpicelli, B. Shiao using Microsoft.NET and SqlServer Like most HTML page-based websites, it is affective, but not engaging or highly interactive. So we looked into ‘Web 2.0’ Technologies to develop a more interactive web site.

Web 2.0 Technologies (We looked into as of October Your mileage may vary).NET + AJAX Controls –Our existing.NET implementation did play well with the AJAX controls. –Image Processing still on the server GWT: Google Web Toolkit –Very easy to write and debug ‘JavaScript’ for ex-Java Programmer –Difficult to perform simple Image Processing and graphics overlay on the client. JavaFX –No Graphical IDE, not fully supported on all platforms/browsers. Silverlight –First Release (October 2007) was not a fully integrated development tool. –Creating all controls (i.e, buttons) from complete scratch. –No Data Grid Control. –Mac and Windows only. JavaScript/XSLT –Steep learning curve. –Browser support issues. –Very fast Table Processing Flex –True image processing on the client –Easy To Learn IDE: ‘Flex Builder’, built on top of ‘Eclipse’

What is Flex? Flex is the collection of technologies developed by Adobe to build interactive web application that run inside a Flash ‘Movie’ plug-in. –Flex SDK, Flex Builder IDE, Flash Player PROS: Flash plug-in is installed in most browsers due to ‘YouTube’ and other similar sites. Flex Builder IDE is very intuitive graphical development environment that makes web development ‘fun’. Truly Write Once – Run Everywhere No Browser or OS Dependencies –(well…almost none) File Upload under Linux did not work, but resolved by forcing upgrade player to version or above. Most browsers now have Flash version 9 and 10. CONS: Flex DataGrid control performance –Lags for displaying large number of rows and columns. (100 rows, 20 columns and beyond) Flash Player 10 ‘Security Feature’ –Broke GalexView (and a lot of other Web Apps that download files to the client). –1 hour required to fix and re-deploy. COST: Flex Builder IDE is FREE for educational research. Flex Builder IDE is $ $700.00, otherwise.

GalexView Architecture Overview GalexView (Flex) Galex ‘SQL’ Web Service (.NET) Galex Database (SqlServer) Query XML Response: DataTable VoTable DataSet Query Simple 3 tiered architecture: GalexView Adobe Flex 3 Client that runs inside the Flash 9.0 Player. Custom Galex ‘SQLs Web Service running inside IIS based on C#.NET 2005 that serves as a direct interface to the Galex Database Galex Database running Microsoft SQL-Server 2000 GalexView is a lightweight data client All queries are held in cache inside the SQL Web Service. Only the currently requested page of results is returned back to the client. All sorting, filtering and page extraction of results takes place on the server.