State of GeoWebCache - FOSS4G 2022

GeoWebCache is a popular open source tile cache server written in Java. GeoWebCache that can be used stand alone, working off a remote WMS or local tile layers, such as MBTiles. However, it's also integrated inside GeoServer, allowing simple and quick configuration, as well as transparent caching of WMS requests that happen to match a cached tile. This presentation will provide information on the latest development for the project, including:

- Performance and scalability improvements
- OGC TileMatrixSet built-in definitions
- Storage of tiles in more blob stores (Swift)
- MBTiles support
- Integration of tile caching in OGC API - Tiles (with GeoServer integration)
- Serving vector tiles and integration with the Mapbox ecosystem (e.g., style editing with Maputnik)
- Continued codebase QA efforts (code clean up, dependency upgrades and the like)

Attend this talk for a cheerful update on what is happening with this project, whether you are an expert user, a developer, or simply curious what it can do for you.

Transcript

1. Andrea Aime
   Simone Giannecchini
   GeoSolutions
   Kevin Smith
   Vivid Solutions
   State of GeoWebCache
   

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2. GeoSolutions
   Enterprise Support
   Services
   Deployment
   Subscription
   Professional
   Training
   Customized
   Solutions
   GeoNode
   • Offices in Italy & US, Global Clients/Team
   • 40+ collaborators, 30+ Engineers
   • Our products
   • Our Offer
   

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3. Affiliations
   We strongly support Open
   Source, it is in our core
   We actively participate in OGC
   working groups and get funded
   to advance new open
   standards
   We support standards critical to
   GEOINT
   

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4. What is GeoWebCache anyways?
   

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5. A tile server!
   • GeoWebCache is a:
   • Java based
   • Stand-alone
   • Tile server
   • Tile protocols supported
   • WMTS
   • TMS
   • TileJSON and XYZ
   • Google Maps XYZ, Bing
   maps QuadKey, KML
   MBTiles
   ArcGIS CC
   

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6. A WMS server!
   • FullWMS option
   • Compose/rescale
   tiles from the tile
   layer
   • Currently single layer
   • Anyone interested in
   sponsoring
   multi-layer support?
   

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7. Based on Tile Sources
   • GeoWebCache can fetch
   (or build) tiles from a
   variety of sources:
   • WMS
   • MBtiles
   • Compact cache
   MBTiles
   ArcGIS CC
   

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8. Using Caches (blobstores)
   • Some layer sources don’t come in tiled form
   • Build tiles and cache them in a BlobStore
   • Different options
   • File system
   • GWC own layout (minimizes files in single directory)
   • XYZ
   • Cloud storage: S3, Azure, Swift
   • SQLite databases
   • Again, pluggable, add your own
   

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9. With Stand Alone Configuration
   • XML file for stand-alone
   version
   • REST API to:
   • Manage layers
   (CRUD)
   • Manage blob stores
   • Run seed/truncate
   jobs
   

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10. Or With GeoServer integration
    • Also runs as a module in GeoServer
    • Point and click configuration
    • A few other perks
    

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11. Tile services
    

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12. TMS and WMS-C
    • Tiled Map Service and Web Map Service -
    Cached
    • The original services from OSGeo
    • https://wiki.osgeo.org/wiki/WMS_Tile_Cachi
    ng
    • https://wiki.osgeo.org/wiki/Tile_Map_Service
    _Specification
    • GeoWebCache was born as “TMS on top of
    WMS”
    • Old, but sometimes still used
    

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13. WMTS
    • The current OGC tiling standard
    • KVP or RESTful
    • Capabilities document with explicit
    time/elevation/dimension support
    

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14. OGC 2D Tile Matrix Set
    • OGC Two Dimensional Tile Matrix
    Set
    • Set of well known gridsets:
    • WebMercatorQuad
    • WorldCRS84Quad
    • UTMxxWGS84Quad (for all
    60 zones, yes)
    • GWC now supports all of them
    out of the box
    

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15. OGC 2D Tile Matrix Set
    • “z” is a pure number in them (not “EPSG:****:z”)
    • Easier to interoperate with XYZ clients
    

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16. TileJSON integration in WMTS
    • Mapbox clients often
    require a TileJSON
    document
    • Documents tile
    pyramid
    • If MVT, describes
    layers and attributes
    • Now exposed in
    WMTS RESTful caps
    document for all
    layers
    {
    "tilejson" :"3.0.0",
    "name":"OpenStreetMap" ,
    "description" :"A free editable map of the whole world." ,
    "version" :"1.0.0",
    "attribution" :"(c) OpenStreetMap contributors, CC-BY-SA" ,
    "scheme" :"xyz",
    "tiles":[
    "https://a.tile.custom-osm-tiles.org/{z}/{x}/{y}.mvt" ,
    "https://b.tile.custom-osm-tiles.org/{z}/{x}/{y}.mvt" ,
    "https://c.tile.custom-osm-tiles.org/{z}/{x}/{y}.mvt"
    ],
    "minzoom" :0,
    "maxzoom" :18,
    "bounds" :[
    -180,
    -85,
    180,
    85
    ],
    "fillzoom" :6,
    "something_custom" :"this is my unique field" ,
    "vector_layers":[
    {
    "id":"telephone",
    "fields":{
    "phone_number":"the phone number",
    "payment":"how to pay"
    }
    },
    {
    "id":"bicycle_parking",
    "fields":{
    "type":"the type of bike parking",
    "year_installed":"the year the bike parking was installed"
    }
    },
    {
    "id":"showers",
    "fields":{
    "water_temperature":"the maximum water temperature",
    "wear_sandles":"whether you should wear sandles or not",
    "wheelchair":"is the shower wheelchair friendly?"
    }
    }
    ]
    }
    

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17. OGC API - Tiles
    • New protocol for
    tile serving by OGC
    • Available only when
    integrated in
    GeoServer
    • Both map tiles and
    data (vector) tiles
    • Spec still in draft,
    and evolving
    

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18. Other services
    • Google maps
    compatible tiles
    • Bing maps compatible
    tiles
    • KML tiles
    • Not satisfied?
    • GWC structure is
    modular, you can add a
    service module to it
    

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19. Tiled layers
    

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20. WMS source
    • The original tile layer!
    • Layer connected to a WMS
    source
    • Filter parameters (style,
    time, elevation, CQL filter,
    env var, pick your own)
    • Supported tile matrix sets
    • Retrieve meta-tiles from
    remote server, store in blob
    store
    

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21. ArcGIS compact cache
    • Tile bundles generated by
    ArcGIS
    • Open specification
    • Contributed by external
    devs
    • Needs a maintainer, know
    anyone that can step up?
    

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22. MBTiles layer
    • Layer connected to a MBTiles
    file
    • SQLite database
    • Table structure defined by open
    spec
    • Can contain a single pyramid of
    tiles
    • Images (PNG/JPEG) or vector
    tiles (MVT)
    • No GeoServer UI integration,
    configure as XML
    

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23. GeoServerTileLayer
    • You don’t see it, but it’s there!
    • Exposes GeoServer own layers
    to GWC when using integration
    • Also allows straight calls the
    rendering engine/data
    

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24. TileLayer is an interface
    • You can add your own tile layer
    implementation
    

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25. Blobstores
    

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26. File blob store
    • Store tiles on file system
    • Configurable layout
    • GWC native (smaller
    directories)
    • XYZ
    • (new) TMS (y axis up)
    • (new) Slippy (y axis down)
    • GWC native: dynamic caches
    • XYZ: seed and set on static file
    server
    0,0
    0,0
    TMS
    Slippy
    

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27. S3 blobstore
    • Store tiles in S3
    • Minio and Cohesity
    compatible!
    • Supports
    • authentication
    • HTTPS
    • proxy
    • Stored as {z}/{x}/{y} (TMS)
    • Can also be used for seeding
    one time static caches
    

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28. Azure blobstore
    • Store tiles in Azure blobs
    • Supports
    • authentication
    • HTTPS
    • proxy
    • Stored as {z}/{x}/{y} (TMS)
    • Can also be used for seeding
    one time static caches
    

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29. Swift blob store
    • Store tiles in OpenStack
    Swift
    • Supports
    • authentication
    • region
    • keystone
    • No GeoServer integration
    yet, can be configured as
    XML
    

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30. SQLite blob store
    • Stores tiles in SQLite databases
    • Not quite MBTiles: uses multiple SQLite
    databases to spread the write load
    (scalability)
    • Driven by a configurable path template
    .
    |-- nurc_Pk50095
    | `-- EPSG_4326image_pngnull
    | |-- 11_2000_1500.sqlite
    | `-- 12_4250_3000.sqlite
    `-- topp_states
    |--
    EPSG_900913image_jpeg7510004a12f49fdd49a2ba366e9c4594be7e4358
    | |-- 6_250_500.sqlite
    | `-- 7_0_0.sqlite
    `-- …
    

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31. BlobStore is an interface
    • You can add your
    own tile layer
    implementation
    • Ideas:
    • Google storage
    • memcached
    • …
    

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32. But also, disk quota
    • Database
    accounting space
    used by tiles
    • Automatic
    cleaning when
    going over given
    quota
    

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33. GeoServer integration
    

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34. Point and click configuration
    

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35. Point and click configuration
    

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36. Integration tricks!
    • “Direct integration”
    • Transparent use of cache if WMS requests do
    match a cached layer
    • Use case: cached tiles by default, switch to
    dynamic rendering if filters are used, don’t even
    change protocol
    • Check the response headers to see which path
    was chosen
    

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37. Automated cleanups
    • Clean up caches
    automatically:
    • When changing
    styles
    • When editing data
    via WFS-T (area
    and zoom
    sensitive)
    

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38. REST interface
    

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39. Configuration
    • Configure
    • GWC basics (e.g. runtime stats)
    • Disk quota
    • Create/update/remove
    • Layers
    • Tile Matrix Sets
    • Blob stores
    

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40. Seeding and cleaning
    • Layer
    • Tile matrix set
    • Format
    • Zoom levels
    • BBOX
    • Filter Parameters
    • Configure tile
    retries, maximum
    number of failed
    tiles, before
    stopping the seed
    job
    

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41. Community
    

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42. Getting GeoWebCache
    • Release Packages
    • SourceForge: GeoWebCache
    • Source
    • GitHub: GeoWebCache
    • Documentation
    • https://www.geowebcache.org/docs
    /current/index.html
    

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43. Communication
    • Users Mailing List
    • geowebcache-users@lists.sourceforge.net
    • Get help
    • Report bugs
    • Developer Mailing List
    • geowebcache-devel@lists.sourceforge.net
    • Plan future development
    • Get help with development problems
    • Please post before you start working on
    something
    

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44. Ways to Contribute
    • Development
    • New Features
    • Bug Fixes
    • Boring Maintenance
    • Testing
    • Test the Release Candidate
    • It’s in your own interest!
    • Documentation
    

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45. The End
    Questions?
    

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