The following sections describe the elements that control the operational and runtime settings used by Oracle Coherence to create, configure and maintain its clustering, communication, and data management services. These elements may be specified in either the tangosol-coherence.xml operational descriptor, or the tangosol-coherence-override.xml override file. For information on configuring caches see the cache configuration descriptor section.
When deploying Coherence, it is important to make sure that the tangosol-coherence.xml descriptor is present and situated in the application classpath (like with any other resource, Coherence will use the first one it finds in the classpath). By default (as Oracle ships the software) tangosol-coherence.xml is packaged into in the coherence.jar.
The root element of the operational descriptor is coherence, this is where you may begin configuring your cluster and services.
Coherence Operational Configuration deployment descriptor should begin with the following DOCTYPE declaration:
|When deploying Coherence into environments where the default character set is EBCDIC rather than ASCII, please make sure that this descriptor file is in ASCII format and is deployed into its runtime environment in the binary format.|
Though it is acceptable to supply an alternate definition of the default tangosol-coherence.xml file, the preferred approach to operational configuration is to specify an override file. The override file contains only the subset of the operational descriptor which you wish to adjust. The default name for the override file is tangosol-coherence-override.xml, and the first instance found in the classpath will be used. The format of the override file is the same as for the operational descriptor, except that all elements are optional, any missing element will simply be loaded from the operational descriptor.
Multiple levels of override files may also be configured, allowing for additional fine tuning between similar deployment environments such as staging and production. For example Coherence 3.2 and above utilize this feature to provide alternate configurations such as the logging verbosity based on the deployment type (evaluation, development, production). See the tangosol-coherence-override-eval.xml, tangosol-coherence-override-dev.xml, and tangosol-coherence-override-prod.xml, within coherence.jar for the specific customizations.
|It is recommended that you supply an override file rather then a custom operational descriptor, thus specifing only the settings you wish to adjust.|
Oracle Coherence provides a very powerful Command Line Setting Override Feature, which allows for any element defined in this descriptor to be overridden from the Java command line if it has a system-property attribute defined in the descriptor. This feature allows you to use the same operational descriptor (and override file) across all cluster nodes, and provide per-node customizations as system properties.
The following table lists all non-terminal elements which may be used from within the operational configuration.
|init-params||filters, services, configurable-cache-factory-config, access-controller, callback-handler|
|packet-buffer||unicast-listener, multicast-listener, packet-publisher|