Publishing GIS Service > Service Types > Map Cache Service

Publishing Map Cache Service

This section will teach you how to publish MapCache service with SuperGIS Server. The basic SuperGIS Server map service enables users to navigate map with front-end application that supports. Since the map is generated by real-time mapping that SuperGIS Server will dynamically transfer the map imagery to display in the front-end according to the area and extent that front-end user is navigating. This has a merit that front-end users can navigate map at any scale; however, if the map data size is too huge or too many users are navigating the same map service at once, due to the real-time mapping, the front-end navigation speed could be influenced. Map Cache Service is the advanced service that is published based on regular Map Service, therefore, the two services use the identical map data. The difference is that Map Cache Service caches the map data into cached imagery based on the defined scale levels and stores them in server-side. Through the pre-mapping Cached imagery created by Cache Map Service, the front-end users can navigate the map service with significantly enhanced performance.

As a result, SuperGIS Server provides the MapCache service, through which you can set the map service that already published as a few levels which has the fixed scales and then SuperGIS Server will make the map data into the Cached images according to the levels you set and store it in server-end. Through MapCache mechanism, the front-end map navigation speed can be significantly enhanced and the problems of huge amount of map data as well as multiple users online navigation can also be well handled. But the shortcoming is that when users browse the map outside the scales you set, the map display might blur.You can create cached map with more scale levels to reduce occurrence frequency of blurred cached map.

Before publishing MapCache services, please make your map data into SGD project file in SuperGIS Desktop and then locate the map data and SGD project file to the machine that SuperGIS Server can access. At last, start to publish the MapCache service.

Publish MapCache Service

1.First of all, publish the map project you built as map service. Please refer to chapter “Publishing Map Service” for detailed workflow.

2.Select the published map service in the “Published Services” area, and click “Config” below to configure the map service.

3.Switch to “Map Cache” tab and check the “Use cache that you define below” box to open map cache service.

4.In “Cache Extent”, you can set cached map origin and its extent.

5.In “Image Settings”, you can set file format, size (in pixel) and quality of resolution (in dpi) of the cached image.

6.In “Cache Scale Definition”, you can set cache scales. There are three ways to create cache scale levels:

　a. Enter number, 10000, in the field and click “Add”; the new scale definition, “1:10000”, will be added into scale definition list. You can repeat this step to set diverse scale levels of map cache service in order you require.

　b. Click “Suggest” and enter break value (i.e. 5 as shown in picture below) in the pop-up dialog; SuperGIS Server will compute scale levels automatically according to the break value you enter.

　c. Select the scale you want in the drop-down menu of “Scale Definition”. SuperGIS Server provides scale levels of Google Map as well; therefore, you can select the scale you want. And use the slide bar to select the scale levels you want to use, then click “Load” to generate a cache service having the same scale levels of Google Maps. Afterwards, you can overlay your map onto Google Maps or Bing Maps.

7.After the settings are completed, click “Done" to accomplish the publishing of Map Cache Service.

Note:

You can create scale definition file whose format is .xml on your own, and save the file in the folder whose path is “C:\Program Files (x86)\Supergeo\Server\WebManager\Scale”; afterwards, you can find and select the scale defined by you in the drop-down menu on SuperGIS Server to publish cache service. The scale file name shows as the name of the .xml file you saved. To do so, you can refer sample below to create scale definition file:

Step 1. Open Notepad

Step 2.Enter content below to add scales “1:1000”, “1:2500”, “1:5000” and “1:10000”.

</ScaleDef>

Step 3. Save the file. Please modify the file extension as “.xml” and save the file in the folder whose path is “C:\Program Files (x86)\Supergeo\Server\WebManager\Scale”.

Note:

If you pre-cached maps using Cache Generator in SuperGIS Desktop, you can use it to generate a cache definition file (*.def) which records the map caches' origin, extent, format, scales, layers, and so on. Therefore, when publishing the pre-cached map, you can use Load from *.def to load all the cache settings and ensure that the cache service use the same cache settings as the pre-cached map. For detailed information on how to publish pre-cached maps, please refer to How to Publish Pre-cached Maps.