Q1: What is Apache NiFi?
Ans: NiFi is helpful in creating DataFlow. It means you can transfer data from one system to another system as well as process the data in between.
Q2: What is NiFi FlowFile?
Answer: A FlowFile is a message or event data or user data, which is pushed or created in the NiFi. A FlowFile has mainly two things attached with it. Its content (Actual payload: Stream of bytes) and attributes. Attributes are key value pairs attached to the content (You can say metadata for the content).
Q3. Can NiFi Flow file have unstructured data as well?
Ans: Yes, FlowFile in NiFi can have both the Structured (e.g. XML, JSON files) as well as Unstructured (Image files) data.
Q4. Where does content of FlowFile stored?
Ans: FlowFile does not store content itself. It stores the reference to the contents, which are stored in the content repository.
Q5. What is a NiFi Processor?
Ans: Processor is a main component in the NiFi, which will really work on the FlowFile content and helps in creating, sending, receiving, transforming routing, splitting, merging, and processing FlowFile.
Q6. What is the Processor Node?
Ans: Processor Node is a wrapper around the Processor and maintain the state about the processor. Processor Node maintains the
- Processors positioning in the graph.
- Configured properties of the processor
- Settings of the Processor
- Schedule states of the processor etc.
Q7. Can NiFi installed as a service?
Ans: Yes, it’s currently supported in Linux and MacOS only.
Q8. What is relationship in NiFi dataflow?
Ans: When a processor finishes with processing of FlowFile. It can result in Failure or Success or any other relationship. And based on this relationship you can send data to the Downstream or next processor or mediated accordingly.
Q9. What is Reporting Task?
Ans: A Reporting Task is a NiFi extension point that is capable of reporting and analyzing NiFi's internal metrics in order to provide the information to external resources or report status information as bulletins that appear directly in the NiFi User Interface.
Q10. Can processor commit or rollback the session?
Ans: Yes, processor is the component through session it can commit and rollback. If a Processor rolls back the session, the FlowFile that were accessed during that session will all be reverted to their previous states. If a Processor instead chooses to commit the session, the session is responsible for updating the FlowFile Repository and Provenance Repository with the relevant information.