What should y you expect in this session? Basic to advanced topics Outline What is map caching? Why should I cache? Caching workflow How to create a c

Transcription

1 Designing, Deploying, and Using Cached Map Services David Crosby & Craig Mesimer

2 What should y you expect in this session? Basic to advanced topics Outline What is map caching? Why should I cache? Caching workflow How to create a cache Caching strategies Clients to the cache Web and desktop More & improvements Questions? 2

3 What is map caching? 3

4 What is a cache?

5 What does it mean to cache a map service? A cached service has a set of map images that have been prerendered for rapid display. 1:500,000 1:250,000 Created at predetermined scale levels Tiles stored on Web server for fast retrieval 5

6 Why Cache Maps? World-Class Cartography WorldBest Performance & Scalability

7 Internet users expect the performance of cached maps. What users expected 10 years ago Dynamically drawn map Slow Compromised cartography What users expect today Cached map Fast Beautiful cartography 7

8 Demo Cache example Orange County Property Appraiser ocpafl org/webmap3/default aspx 8

9 Caching g Workflow Select coordinate system and scales. Author and publish your map document. Set up tiling scheme. Create tiles. tiles 9

10 1. Choose coordinate system y and scales. Choose from wellwell-known tiling schemes of Web map services: ArcGIS Online (new and old) Google Maps & Bing Maps Import from file or service. Create your own. 10

11 Choosing g your y own scales Build just the scales you need. Determine D t i closest l t required i d scale. Double scale denominator until full extent is reached. reached Adjust smallest scale to full extent of map service. Sample 10 level cache Level Scale 1 Tiles % of total 0.000% 2 1:16,000, :8,000, :4,000, % 4 1:2,000, % 5 1:1,000, % 6 1: :500, , % 0.293% 7 1:250,000 4, % 8 1:125,000 16, % 9 1:62,500 65, % 10 1:31, , % 0.001% Final level is always ~75% of the total. 11

12 Organizing cached services With others in your organization Departments should agree on cache properties. With online content ArcGIS Online Google Maps Bing Bi Maps M Best practice Use same coordinate system and tiling g scheme for all caches. Transportation p Hydrography Land Base 12

13 Demo Load scales for map document New tiling scheme using Web Mercator Auxiliary Sphere (WKID ) Old tiling scheme still available, but will be removed 12/22/arcgis--online 12/22/arcgis online--maps maps--updated updated--and and--migrated migrated--to to--google google-maps--bing maps bing--maps maps--tiling tiling--scheme.aspx Google and Bing scale levels available under the Designing a map to overlay Google Maps or Bing Maps help topic esigning_overlay_gm_mve.htm 13

14 2. Author and publish map. Choose a set of scale levels and design at those. ArcGIS Online, Google Maps, Bing scales, or your own? Add the scales to the ArcMap dropdrop-down list. Make the map look good at each scale. Copy layers. Can set a different scale range and symbology for each copy Group p layers y by y scale level. Only have to set the scale range at the group layer level 14

15 Map authoring g tips Background color Data frame (ArcMap) background = transparency color Transparent p color defaults to near white (253, (, 253,, 253). ) Explicitly define a background color that is not already in your map. Use the Maplex labeling engine for MXDMXD-based map services as this will give the best label placement during caching. g 15

16 Demo Author the map and publish it. Design at viewing scales Grouping layers together Layer generalization Scale--level labeling considerations Scale 16

17 3. Set up tiling g scheme. Cache creation tools Properties of a cache Tiling scheme Tile size DPI Scales Origin Image format and compression Antialiasing Fused or multilayer 17

18 New caching dialog box at 9.3 reflects multistep process. Set S the h tiling ili scheme, h then h create the h tiles. il Use Manage Map Server Cache Tiles tool for both create and update. Cannot change tiling scheme after clicking OK or Apply. 18

19 Caching tab is also available in Manager in 9.3. You Y can use it to t Define the tiling scheme for a service. Enable cache on demand. You cannot use it to launch the caching tools. 19

20 Tile size and DPI Tile size Pixel dimensions of each image 256 x 256 and 512 x 512 are de facto standards standards. ArcGIS Online previously used 512 x 512, but now uses 256 x 256. Google Maps and Bing Maps use 256 x 256. Use caution outside these sizes. Larger dimensions are faster to build, but tiles take longer to download. DPI Resolution of the cache tiles that the server will generate Set higher than default (96) if clients printing cached services. Use caution when changing default. default Symbol sizes are affected by dpi. 20

21 Choosing output image type Transparency # of colors Storage Best for JPEG No 16 million Lossy ((1%-100% compression) p ) Raster PNG8 Yes 256 Lossless Vector PNG32 Yes 16 million Lossless Raster / Vector PNG24 Yes ((No in IE 6)) 16 million Lossless Raster / Vector Data Frame (ArcMap) Background = transparency color Raster and Vector Data 512 X 512 pixels JPEG = 40 KB PNG32 = 189 KB PNG24 = 178 KB PNG8 = 92 KB JPEG = 43 KB PNG32 = 22 KB PNG24 = 21 KB PNG8 = 14 KB Vector Only Data 512 X 512 pixels A 21

22 Tips for choosing a cache image format Transparency # of colors Storage Best for JPEG No 16 million Lossy ((1%-100% % % compression) p ) Raster PNG8 Yes 256 Lossless Vector PNG32 Yes 16 million Lossless Raster / Vector PNG24 Yes ((No in IE 6)) 16 million Lossless Raster / Vector Use PNG8 for overlay services. Boundaries, street network for overlaying imagery, etc. Use JPG image format for basemaps basemaps.. Compression quality = lower means smaller/faster files Avoid PNG24 with Web applications. IE 6 does not honor transparency in PNG /10/17/Tips-for-choosing-a-cache-imageformat.aspx

23 Basemaps (aerials): Image format guidelines Many colors colors Continuous symbology Compression range for JPEG: 55 (aerials) 90 (vectors) JPEG 55 / 45.5K JPEG 90 / 116K 23

24 Antialiasing No antialiasing Antialiasing Smooths edges of labels and lines by blending them with the background Choose background color carefully! Cannot set this up in ArcMap for caching - use the caching tools. Takes longer to cache Note N t th thatt antialiasing ti li i IS now available il bl with ith optimized ti i d map services. i 24

25 Fused or Multilayer y Fused Single image tiles for all map layers at each scale level Best performance No control over individual layer visibility Multilayer Image tile for each map layer at each scale level Only practical with ArcMap clients Avoid with Web applications pp Blending on Web tier reduces scalability and performance. Internet users expect the performance of fused cached maps. 25

26 Fused vs. Multilayer y Caches Create Map Server Cache Tool Advanced Cached Service Properties Fused caches are recommended for the full performance benefits of server caching.

27 Demo Set Up Tiling Scheme 27

28 4. Create tiles. Manage Map Server Cache Tiles New tool at 9.3 Similar to Update Map Server Cache Tiles at 9.2 Allows fine fine--grained control over scales that are cached Launch this tool from ArcCatalog by clicking Create tiles or Update tiles in the Caching tab of Service Properties ArcToolbox Command prompt Scripting p g environment such as Python y Service must be started to create tiles. Use N+1 instances where N = the number of cores on server. 28

29 Demo: Create tiles. Tools in ArcCatalog for caching Cache folder structure JavaScript Ja asc pt app applications cat o s s showing o g cac cached ed a and d dy dynamic a c maps aps Fiddler & Firebug

30 Demo: Create tiles. Portland (Notification): ArcGIS Online (Site Selection): Fiddler & Firebug

31 Clients to Cached Map Services ArcMap (2D) ArcGlobe and ArcGIS Explorer (3D) pp g Applications pp ArcGIS Web Mapping.NET, Java, JavaScript/Flex/Silverlight ArcGIS for AutoCAD OGC clients (Gaia, etc.) Google Maps, Bing Maps, and Google Earth

32 WMS services take advantage g of cache. 1. Enable WMS capability on a cached map service. 2. WMS service uses cached images instead of generating an image on the fly. Only uses cache when there is no need to change projection, layer order, layer visibility, background, etc. 32

33 Using g caches in Web applications Navigation limited to the tiling scheme scales Tiles cannot be reprojected. reprojected. ArcGIS Online mashups Map must use Web Mercator coordinate system. system Must use ArcGIS Online tiling scheme Google Maps and Bing Maps mashups Map must use WGS 1984 Web Mercator coordinate system Must use Microsoft Bing/Google Maps tiling scheme 33

34 Using g caches in ArcGIS Desktop ArcMap High level of control over tile appearance Continuous zoom Supports reprojection not the best idea Can easily overlay with other services and data ArcGIS Explorer Can overlay 2D cache on globe surface ArcGIS Online tiling scheme recommended Must clear local cache after update 34

35 Desktop clients and cache updates ArcGIS Desktop and ArcGIS Explorer maintain local caches. Users must clear local cache to see updates. User can disable local caching. Server S administrator can also disable local caching. New at 9.3 Overrides client settings 35

36 Client--side ArcMap parameters Client ArcMap creates a local cache. Located: %temp% %temp%\\esrimapcache\ esrimapcache\ Can get out of sync with server server--side cache Administrator can allow/disallow client caching. ArcMap users can also control caching behaviors.

37 Caching strategies 37

38 Cache size affects strategy Small caches Create all tiles. Update all tiles frequently. Large caches Create the most accessed areas first. Create tiles on demand. Update strategically. 38

39 Cache by feature class Cache only within boundary of features you supply. You can supply a feature class with just one feature. Avoid numerous features or geographically small features. Saves time and disk space Optionally, Optionally track the status of which features have been cached. Tips--for Tips for--caching caching--by by--feature feature--class.aspx 39

40 On--demand caching On Creates tiles as they are visited by users and add them to your cache. First visitor to an area must wait for tiles to be created. Precreate tiles for areas that you anticipate will be most popular. Set as a service property in ArcCatalog or Manager. 40

41

42 Cache by y feature class + cache on demand Southern California populated places example 42

43 Updating g the cache Necessary if you want to see changes in your data Gives you the performance benefit of caching, even with changing data Update with Manage Map Server Cache Tiles tool Execute manually or via a scheduled script See the help for an example Python script 43

44 Strategic g updates Geoprocessing model can be used to update only areas that have changed. Custom geoprocessing tool: Show Edits Since Reconcile Use geodatabase versioning to track changes. Generate a feature class of where changes g have occurred. Update the cache using feature class output. Repeat on a regular basis. 44

45 Update a cache using a staging server (scenario) Production ArcGIS Server Instance Staging ArcGIS Server Instance Map service on production server has layers to support queries and TOC. parcels Map service on staging server has all layers to support cache creation. Queries File Geodatabase parcels Xcopy or X Securecopy or Cache folder C h ffolder Cache ld Display p y #2 #1 Show Sho Edits Since Reconcile + Cache Rebuild Python script One-Way OneReplication Multiuser Versioned Geodatabase

46 Globe caches 3D globe caches give optimal performance in ArcGlobe and ArcGIS Explorer. Image format and tiling scheme is preconfigured. Requires a globe service and use of globe caching tools. 46

47 Creating g a 3D globe g cache from a 2D map cache Create a 3D cache from a globe containing a draped 2D map cache. Gives better cartographic g p quality q y and performance p than you y would get if you authored the.3dd in ArcGlobe This is how ESRI created the ArcGIS Online g globe caches. For instructions, see ArcGIS Server Development Blog post: Creating a 3D globe cache from a 2D map cache 0/Creating--a-3D0/Creating 3D-globe globe--cache cache--from from--a-2d2d-mapmap-cache.aspx 47

48 9.3 to Improvements Optimized map services were introduced at 9.3.1: Ensures designers adhere to best map design practices S l dependencies Scale d d i Mixed projections Unsupported (slow) data types like TINs Using MSDs will improve i the computation time required to generate cached map services. If you do not use MSD files to create your map service, use the map optimization toolbar to make some decisions. Will optimized map services negate the need for a cache? 48

49 Add and remove scales from an existing g cache. Use the Manage Map Server Cache Scales tool. Edits the cache configuration and the cache folders on disk 49

50 Improvements to ArcMap as a client Improved display of resampled cached tiles Improves the look of ArcGIS Online StreetMap Helps eliminate issues like disappearing boundaries 50

51 Updated documentation Caching help greatly expanded between 9.2 and 9.3 and Web help is constantly updated. Web help is available at ArcGIS Server Development p Blog gp posts address specific p problems and are later moved to the Web help. 2/Strategies--for 2/Strategies for--large large--caching caching--jobs.aspx 51

52 Training g ArcGIS Server: Web Administration Using the Microsoft.NET Framework Two full lessons on map caching Free Live Training Seminar Implementing and Optimizing ArcGIS Server Map Caches Demo driven Focuses on strategies Available from ESRI Virtual Campus Visit training.esri.com for more information. 52

53 Questions? Thank you! Please remember to fill out your survey. 53