Dev Summit Final Day

Day 3 Thurs Mar 22

I’m finally getting a chance to blog about this now. Steve, I, and nearly 2 dozen other attendees got totally screwed by the storms in Phoenix. However, at least we didn’t have to sit on the tarmack for nearly 3 hours like the other group waiting at the same gate. Though, by the time I got home 25 hours after leaveing the conference, sleeping in the Phoenix airport and eating only pretzals and snack mix; that wait seemed pretty trivial. I hope everyone else also eventually got home safely.

General Thoughts

This was a short day. Only 2 sessions and then the lunch & closing session. It seemed that about 25-30% of the folks had already left and a number of the ESRI devs had left as well. The sessions seemed a bit less technical that those on Wensday.

Sessions Attended

Building & Using ArcGIS Server Map Caches (Best Practices)

The MapCache is a tile cache created by rasterization & tile cutting of the data you have presented in your MXD. The main take home points of this talk were:

• Understand what a tiling schema is 1st
• Design your tiling schema BEFORE trying to build on for production use
• Design a SINGLE schema that will serve the entire organization and all your data layers. In other words: Level 10 = the same scale for regardless of which layer you are building from; Tile sizes should be equal across various data sources; Use same origin point for all caches.
• Client can rapidly reproject data to any projection system so use one that makes the most sense for both your data and web services methods (ideally, Geographic).
• DO NOT use png24. PNG8 best if you need transparency, JPG best if you don’t need transparencey.
• Smaller tile sizes (128×12 do not neccessarily result in faster performance over the web, while they take 5 times as long to produce & take up significantly more storage space than large ones (512×512). Test to make sure performance improvement is worth the extra effort. Use the largeest tiel size you can.
• Fuse as many layers together as possible to create your base map caches. Therefore instead of Intermitten Streams, Permanent Streams, Rivers, & Lakes all being separate caches, they would be a single Hydrography cache that would appear as a single layer in the map service.
• Each zoom level should be cartographically distinct
• Forcing an ExportMapImage call from a web service can be a big performance hit. Understand what would make a client do that and avoid it as much as possible.
• Building large many leveled caches can be VERY time consuming (days-weeks for worldwide layers). Pick a small area, TEST-TEST-TEST and then TEST before doing the full export, instead of having to do it over & over.
• Cache will build over the extent of your MXD if the layer(s) you are building a cache for don’t have data in the full extent, background color tiles will be created. A waste of CPU time & storage space.
• Dynamic cache building (a la TileCache) is planned for future releases.

Creating Windows & Web Apps with WPF

This was not at all about GIS. It was strictly on WPF.

WPF is very powerful & can provide you with a lot of UI design patterns.

Security & Permissions can be tightly controlled. Each app runs in a security sandbox. App origin, app settings, and client settings all interact to chose the most restrictive security level for the app.

You can do stuff with this technology TODAY. But, it’s real power won’t be realized until Visual Studio ORCAS is released and Vista or .Net 3 runtimes are more widely accepted. The 1 code for web & desktop paradigm is only for IE6+ with .Net 3 runtime right now. Must use WPF/E for other browser support.

Closing Session

Open Q&A after lunch. No really hard questions were asked, but Steve & other continued to point out that the extra cost of putting the ADF on a separate server is just not reasonable, and that the overall cost of ArcGIS Server is too high.