Universal Event Listeners
Since 2.10
Universal Event Listeners allow you to write a piece of
Groovy code that controls when an event is triggered, subsequently executing a predefined task.
The Groovy code is periodically executed and when it returns TRUE, the task is executed.
Table 33.7. Attributes of Universal message task
| Attribute | Description |
|---|---|
| Node IDs to handle the event | In a Cluster environment, each universal event listener has a Node IDs attribute which may be used to specify which Cluster node performs the Groovy code. There are following possibilities:
In a standalone environment, the Node IDs attribute is ignored. |
| Interval of check in seconds | Periodicity of Groovy code execution. |
| Groovy code |
Groovy code that evaluates either to |
Groovy code
A piece of Groovy is repeatedly executed and evaluated; based on the result, the event is either triggered and the task executed or no action is taken.
For example, you can continually check for essential data sources before starting a graph. Or, you can do complex checks of a running graph and, for example, decide to kill it if necessary. You can even call the CloverDX Server Core functions using the ServerFacade interface, see Javadoc: http://host:port/clover/javadoc/index.html