Interview Questions.

Q1. Do The Attributes Get Added To Content (real Data) When Data Is Pulled By Nifi ?

You can honestly add attributes for your FlowFiles at each time, that’s the entire point of isolating metadata from the actual records. Essentially, one FlowFile represents an object or a message moving thru NiFi. Each FlowFile carries a bit of content material, that's the real bytes. You can then extract attributes from the content, and keep them in memory. You can then operate in opposition to the ones attributes in memory, with out touching your content. By doing so you can keep a whole lot of IO overhead, making the whole drift management process extremely efficient.

Q2. What Is A Nifi Custom Properties Registry?

You can use to load custom key, fee pair you could use custom houses registry, which can be configure as (in nifi.Residences file)

nifi.Variable.Registry.Properties=/conf/nifi_registry

And you may put key value pairs in that file and you may use that homes in you NiFi processor the use of expression language e.G. $OS , if you have configured that assets in registry record.

Q3. What Is The Template In Nifi?

Template is a re-usable workflow. Which you may import and export inside the same or one of a kind NiFi instances. It can shop lot of time in preference to creating Flow again and again each time. Template is created as an xml document.

Q4. Does Nifi Works As A Master-slave Architecture?

No, from NiFi 1.0 there's zero-master philosophy is considered. And each node within the NiFi cluster is the equal. NiFi cluster is controlled via the Zookeeper. Apache ZooKeeper elects a single node because the Cluster Coordinator, and failover is dealt with routinely by way of ZooKeeper. All cluster nodes record heartbeat and status data to the Cluster Coordinator. The Cluster Coordinator is answerable for disconnecting and connecting nodes. Additionally, each cluster has one Primary Node, also elected by way of ZooKeeper.

Q5. How Do You Define Nifi Content Repository?

As we mentioned previously, contents aren't saved in the FlowFile. They are stored in the content material repository and referenced by means of the FlowFile. This lets in the contents of FlowFiles to be saved independently and efficiently based totally on the underlying storage mechanism.

Q6. What Is Apache Nifi?

NiFi is useful in growing DataFlow. It me you can trfer information from one device to any other machine as well as method the records in between.

Q7. How Does Nifi Support Huge Volume Of Payload In A Dataflow?

Huge volume of facts can trit from DataFlow. As information moves through NiFi, a pointer to the statistics is being exceeded round, called a FlowFile. The content of the FlowFile is most effective accessed as needed.

Q8. What Is A Nifi Processor?

Processor is a first-rate element in the NiFi, which will in reality paintings on the FlowFile content and allows in developing, sending, receiving, trforming routing, splitting, merging, and processing FlowFile.

Q9. Is There A Programming Language That Apache Nifi Supports?

NiFi is carried out within the Java programming language and permits extensions (processors, controller offerings, and reporting responsibilities) to be applied in Java. In addition, NiFi helps processors that execute scripts written in Groovy, Jython, and numerous different famous scripting languages.

Q10. What Is The Bulleting And How It Helps In Nifi?

If you want to understand if any troubles arise in a dataflow. You can check within the logs for something thrilling, it's miles a good deal greater convenient to have notifications pop up at the display. If a Processor logs something as a WARNING or ERROR, we can see a "Bulletin Indicator" show up in the pinnacle-proper-hand corner of the Processor.

This indicator seems like a sticky notice and will be proven for 5 mins after the occasion occurs. Hovering over the bulletin gives records about what befell in order that the user does no longer ought to sift thru log messages to locate it. If in a cluster, the bulletin will also imply which node within the cluster emitted the bulletin. We also can change the log degree at which bulletins will arise within the Settings tab of the Configure conversation for a Processor.

Q11. What Happens, If You Have Stored A Password In A Dataflow And Create A Template Out Of It?

Password is a touchy belongings. Hence, whilst exporting the DataFlow as a template password could be dropped. As soon as you import the template inside the equal or extraordinary NiFi device.

Q12. What Is Reporting Task?

A Reporting Task is a NiFi extension factor this is able to reporting and reading NiFi's inner metrics so as to offer the records to outside resources or record repute data as bulletins that seem at once in the NiFi User Interface.

Q13. What Is The Backpressure In Nifi System?

Sometime what takes place that Producer system is faster than patron system. Hence, the messages which might be consumed is slower. Hence, all of the messages (FlowFiles) which are not being processed will stay within the connection buffer. However, you may restrict the relationship backpressure length either primarily based on variety of FlowFiles or wide variety of facts size. If it reaches to defined restriction, connection will supply lower back strain to producer processor no longer run. Hence, no greater FlowFiles generated, until backpressure is decreased.

Q14. What Is Nifi Flowfile?

A FlowFile is a message or occasion statistics or person records, that is pushed or created inside the NiFi. A FlowFile has specifically two matters connected with it. Its content (Actual payload: Stream of bytes) and attributes. Attributes are key fee pairs connected to the content (You can say metadata for the content material).

Q15. What Is Relationship In Nifi Dataflow?

When a processor finishes with processing of FlowFile. It can result in Failure or Success or some other courting. And primarily based in this relationship you could send records to the Downstream or subsequent processor or mediated accordingly.