In nationwide-scale visualization and interaction scenarios, to ensure rapid preview of large-scale vector data, iServer provides vector precache and raster precache production capabilities for vector tiles service V2. The results can be configured into services to improve map rendering efficiency. This section introduces the specific configuration process and precautions.

Operation Steps

Entry Point:

  • service management Home -> Cluster -> tile management tab -> Select Service

Operation Instructions:

(1) Vector Precache Production

On the Select Service page, after filtering out the rest vector tile service V2 through the service type filter, hover the mouse over the specified service card to display the Vector Precache Production button. Click it to enter the relevant configuration page. The supported parameters are as follows:

  • Tile Settings
    • Tile Levels: Supports selecting cache levels for tiling by dragging. The selectable levels range from 0 to 25, with a default of 7-16.
    • Tile Format: Currently only MVT format is supported.
    • Tile Size: The size of each generated tile, in pixels. Currently only 512*512 pixel tiles are supported.
    • Tile Extent: Used to set the geographic extent for tile generation, in the format: -180, -90, 180, 90. Defaults to the full map extent.
    • Tile Origin: The starting coordinate point for calculating tile row and column numbers. Defaults to the top-left corner of the tiling extent.
  • Storage Settings
    • storage type: The storage method for vector tiles. Currently only geotrellisfile is supported.
    • Storage Format: Original and Compact. When the tile storage format is Original, tile files are stored on disk as individual image files without data compression and can be read directly. Map tiles data is intuitively represented as original images in multiple folders. Compact tiles apply certain compression and encryption mechanisms to the original tile files, including two parts: index files (*.sci) and tile data. The tile data structurally uses a group of files to replace the original format, and tile data under different scale folders will be stored as a group of files (*.cf). Currently only Original is supported.
    • Tile Name: The tile name, corresponding to the folder name for storing tiles. Defaults to the same as the service name. Currently not configurable.
    • Storage Path: The storage path for generated tiles. The default value is the default output path (output) of the current product package. Currently not configurable.
  • advanced settings
    • enable Scheduled Tiling: Supports checking. After checking, you can set and add tiling time periods. Tiling tasks will only execute during allowed periods. When exceeded, they will pause and then continue when the next allowed period begins, until tiling is complete.

(2) Raster Precache Production

On the Select Service page, after filtering out the rest vector tile service V2 through the service type filter, hover the mouse over the specified service card to display the Raster Precache Production button. Click it to enter the relevant configuration page. After entering the page, click the Generate Raster Precache button after the specified map in the map list below the service to configure raster precache parameters for the map with the specified style. The supported parameters are as follows (Note: when the service has not completed vector precache production, this button will be grayed out):

  • Tile Settings
    • Tile Levels: Supports selecting cache levels for tiling by dragging. The selectable levels are affected by the vector precache levels. The maximum level for raster precache can only be selected from existing vector tiles levels.
    • Tile Format: Currently only PNG format is supported.
    • Tile Size: The size of each generated tile, in pixels. Two pixel sizes are available: 256*256 and 512*512. The default is 512*512.
    • Tile Extent: Used to set the geographic extent for tile generation, in the format: -180, -90, 180, 90. Defaults to the full map extent.
    • Tile Origin: The starting coordinate point for calculating tile row and column numbers. Defaults to the top-left corner of the tiling extent.
  • Storage Settings
    • storage type: The storage method for raster tiles. Currently only geotrellisfile is supported.
    • Storage Format: Original and Compact. When the tile storage format is Original, tile files are stored on disk as individual image files without data compression and can be read directly. Map tiles data is intuitively represented as original images in multiple folders. Compact tiles apply certain compression and encryption mechanisms to the original tile files, including two parts: index files (*.sci) and tile data. The tile data structurally uses a group of files to replace the original format, and tile data under different scale folders will be stored as a group of files (*.cf). Currently only Original is supported.
    • Tile Name: The tile name, corresponding to the folder name for storing tiles. The default rule is {service name_style name}. Currently not configurable.
    • Storage Path: The storage path for generated tiles. The default value is the default output path (output) of the current product package. Currently not configurable.
  • advanced settings
    • enable Scheduled Tiling: Supports checking. After checking, you can set and add tiling time periods. Tiling tasks will only execute during allowed periods. When exceeded, they will pause and then continue when the next allowed period begins, until tiling is complete.

View Task List

After creating a task, you can click View Task List to see all precache production tasks on the current server on the tile management -> Task page. You can filter tasks by task status and search for tasks by tile name or service name.

You can view the task ID, tile name, service name, creation time, task duration, status, tile type, and tile format of all tasks. You can also view the basic information, progress information, etc. of each task.

You can also stop running tasks, start or delete paused tasks. You can click the tile name in the task list to view more detailed task information, progress information, and work progress at each scale. You can restart tasks to re-tile.

Monitor Tiling Process

On the Task page under Running Tasks, click the tile name in a created precache production task to view task status information. This includes the storage information for generating precache, tiling configuration information, overall task progress table (dynamically displaying tiling speed and time), task time statistics, storage occupied by generated tiles (occupied storage and estimated storage space required). You can also perform management operations such as "Pause", "Start", and "Delete" on tasks, and monitor the working status of each TileWorker in the task.

Precautions

  • Raster precache is suitable for performance improvement in map rendering scenarios with relatively fixed styles of land type patch data. It is not recommended to use it when frequent dynamic style changes are needed during map browsing.
  • Raster precache is produced based on existing local vector tiles. The actual number of tiles produced equals the number of existing local vector tiles.

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