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WMS_BASE_URL (string): url that will be reported in the GetCapabilities response as URL to be used to request maps.
WMS_CLIENT_CACHE_TIMEOUT (integer): Timeout of the cache in seconds, that is sent to the browser. default is 300 seconds (15 minutes). To disable caching, set the timeout to 0.
- WMS_ALLOWED_GRID_PLOT_GROUP_ID (string): Id of the grid plot group which layers will be made available in the WMS service. If not configured, all layers are available.
- WMS_IMAGE_MAX_WIDTH_HEIGHT (integer): The maximum size of the WIDTH and HEIGHT product GetMap parameters. The default is set to 2304000 (the full HD resolution of 1920x1200). N.B.: The higher this value is set, the more memory is required to generated the WMS images.
- WMS_MAX_NUMBER_OF_CACHED_LAYERS (integer, since 2019.02): The maximum number of layers that are chached cached in the WMS services. The default is 100. The optimal number depends on the amount of memory available and the number of configured layers and the size of the layers. When the WMS runs into Out Of Memory issues, the size of the number should be lowered or the memory increased.
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Since the WMS service is stateless, it can be scaled both vertically (more cpu and memory) and horizontally (more tomcat instances)..
Tomcat itself can also be tuned by specifying the number of concurrent requests. In case memory errors occur, the tomcat server.xml can be tuned to limit the number of concurrent requests. In the tomcat server.xml the maxThreads parameter specifies the maximum number of concurrent requests that are allowed. For Tomcat 7 this is set to 200 by default, which is quite a lot for a WMS service. See the following example where the tomcat server.xml has been configured with a maximum of 50 threads.
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