NiFi Components

NiFi provides several extension points to provide developers the ability to add functionality to the application to meet their needs. The following list provides a high-level description of the most common extension points:

• Processor

  • The Processor interface is the mechanism through which NiFi exposes access to FlowFiles, their attributes, and their content. The Processor is the basic building block used to comprise a NiFi dataflow. This interface is used to accomplish all of the following tasks:

    • Create FlowFiles

    • Read FlowFile content

    • Write FlowFile content

    • Read FlowFile attributes

    • Update FlowFile attributes

    • Ingest data

    • Egress data

    • Route data

    • Extract data

    • Modify data

• ReportingTask

  • The ReportingTask interface is a mechanism that NiFi exposes to allow metrics, monitoring information, and internal NiFi state to be published to external endpoints, such as log files, e-mail, and remote web services.

• ControllerService

  • A ControllerService provides shared state and functionality across Processors, other ControllerServices, and ReportingTasks within a single JVM. An example use case may include loading a very large dataset into memory. By performing this work in a ControllerService, the data can be loaded once and be exposed to all Processors via this service, rather than requiring many different Processors to load the dataset themselves.

• FlowFilePrioritizer

  • The FlowFilePrioritizer interface provides a mechanism by which FlowFiles in a queue can be prioritized, or sorted, so that the FlowFiles can be processed in an order that is most effective for a particular use case.

• AuthorityProvider

  • An AuthorityProvide is responsible for determining which privileges and roles, if any, a given user should be granted.