In the previous sections, we have seen how applications can be specified and how custom operators can be developed (with an example for configurable property). Most operators have properties that need to be configured, for example, a file reader will need to be supplied with the directory path or a Kafka consumer the broker address and topic. Whoever deploys the application needs to know and be able to supply values for these properties.
In addition to properties that are directly related to the functionality of an operator, there is another category of settings called attributes that control behavior of the platform (as opposed to the functionality of operators).
Attributes are defined for three different scopes:
- Application: Platform behavior for the application as a whole, such as streaming window interval, container JVM options, container heartbeat interval and timeout, and so on. See the complete list of attributes here https://ci.apache.org/projects/apex-core...