How to Update Tile

When SuperMap iServer Distributed Tiling Service is used, map tiles of multiple scales can be generated at the same time, and map tiles can also be generated for a specified range. The generated map tiles can be used directly on the server side or offline. However, if the map data in the map services is changed, for example, the style of a certain layer in the map is changed, or the elements of a certain layer are added/deleted/modified, the existing map tiles need to be updated to ensure the timeliness of the map tiles.

If the map data is changed, you do not have to worry that the drawing effect is the old data when using the tile data. The system will judge whether each tile is expired. If it is expired, it will dynamically draw according to the new map data. For outdated tile data, you can choose to let the system automatically update and overwrite the outdated tiles while plotting, or you can choose to set the tiles as read-only and manually update the tiles by using the distributed graph cutting service.

Considering that the data volume of the map service is usually large, the efficiency of automatically updating tiles is definitely not as good as the multi-node efficiency of the distributed parallel graph cutting service. Therefore, it is recommended that you update tiles manually or use the tiles update tool to update tiles.

• Update and append tiles manually
• Tile updating tool
  • Methods
  • Directional update
  • Note
• Remove tiles with specified bounds

Update and append tiles manually

The distributed tiling service of SuperMap iServer supports updating and appending new tiles into the existing tiles. For instance, to update or append new tiles with certain scales or certain bounds into the existing tiles. The tile formats that support updating and appending are: MongoDB, SMTiles, MBTiles, UGCV5 (raster based), SVTiles (vector based).

The steps of the "update and append tiles manually" are identical with How to use Distributed Map Tiling service. You need to select a path to place the tiles (such as output path\sqlite\) or to the tile library (determined by storage ID). Meanwhile, you should specify the scale and the bound that you want to append. If a new tile is identical with the existing tile, the old one will be replaced.

As for the distributed tiles, there will be prompted with "The tiles exist. Do you want to create a new tiling version？“ before starting to tile. In this case, you should select No, and select an exist version for updating or appending. Then, click OK.

Tile updating tool

SuperMap iServer provides the tile updating tool, which supports the mutual import of map tiles stored in MongoDB, SMTiles, and UGCV5.

By using this tool, you can:

• Update tiles from other tile packages
• Merge tiles scattered in different storage location
• Export tiles with specified scale and range stored in distributed slice set into file format (such as SMTiles) for easy distribution

Methods

Log in to the service management tool, and click "Service", "Advanced", and "Tiles Update" to start using the tiles update tool. The usage method is as follows:

1. Click "Create tiles update task" to enter the task creation page
2. Sets the "Input tile set", the source of the update tiles data
3. Set the "target tile set", the tile package to be updated, or the tile package to be updated or modified
4. Select the scale to be updated in the "Input tile set scale" list automatically read out by the system, and click the "Add" button
5. Set the update range, which defaults to the maximum range of tiles
6. Click the "Start Update" button

Directional update

You can also directly update the tile file being used by the map component or service providers. Click "Update tile" on the configuration page to link to the tiles update tool:

• For the map service component which starts the tiles, you can choose a tile type on the configure page, and click the "Update tile" link under the "Storage Location".
• For the map service provider of the tile package (e.g., SMTiles), you can click "Update tile" link under the "File Path" on the configuration page.

Note

To ensure the correctness of the data after the tiles are updated, please consider the following aspects when updating the tiles:

• Before updating tiles, make sure that the tiles of the map with the same name in the input tile source and the target data to be updated have the same tile format, such as tile size, transparency, etc
• For non-distributed storage tiles such as SMTiles and UGCV5, in addition to the above image requirements, the "Input tile set" and the current "Target tile set" to be updated must correspond to the same map
• The name of the directory where the tile package is saved should be consistent with the CacheName in the tile config file (such as the.sci file) and cannot be changed independently.
• The UGCV5 compact cache does not support updates to MongoDB tile sets.

Remove tiles with specified bounds

If all the data in the geographical range has changed and all the caches need to be updated, you can clear the cached images in the geographical range through the clearCache resource, and then regenerate the cache.

For example, to clear the world map cache for longitude 120°~150° and latitude 30°~50°, enter the following URI address:

Hhttp://supermapiserver:8090/iserver/services/map-world/rest/maps/World Map/clearcache.rjson?bounds={"rightTop":{"y":50,"x":150},"leftBottom":{"y":30,"x":120}}.

Clear succeeded, return true.

It should be noted that when using the clearCache resource, if a geographic range is specified, all cached images within the geographic range, as well as cached images that intersect with the geographic range, will be cleared.