What is Apache Beam?
Apache Beam is a unified programming model used in defining and executing data processing pipelines. These Pipelines consist of ETL, batches, and stream processing. The beam is an open source based on Apache Software Foundation. Apache Beam is used in simplifying the mechanics of large-scale data processing, by using Apache Beam SDKs, we can build a program that defines the pipeline.
What is the process of Apache Beam?
Apache Beam is used in transforming PCollection as input and output in each step of the Pipeline.It also can hold a dataset of a fixed size by updating the data source.
Here are 25 Apache Beam interview questions along with concise answers:
1. What is Apache Beam?
Answer: Apache Beam is an open-source, unified programming model for data processing. It provides a high-level API that allows you to write batch and streaming data processing pipelines that can run on various execution frameworks.
2. What are the key components of Apache Beam?
Answer: The key components of Apache Beam are Pipeline, PCollection, Transforms, I/O Connectors, and Runners.
3. What are the advantages of using Apache Beam?
Answer: Advantages of Apache Beam include portability, unified API, extensibility, and fault tolerance.
4. What are the different windowing options in Apache Beam?
Answer: Windowing options in Apache Beam include fixed windows, sliding windows, sessions, and global windows.
5. What are side inputs in Apache Beam?
Answer: Side inputs allow a transform to access additional data during processing, enabling lookups or data enrichment.
6. What is the role of Apache Beam runners?
Answer: Runners execute the Beam pipeline on a specific execution framework, translating pipeline constructs into operations supported by the engine.
7. How does Apache Beam achieve fault tolerance?
Answer: Apache Beam achieves fault tolerance through mechanisms like data checkpointing and resuming from the last successful checkpoint.
8. What is watermarking in Apache Beam?
Answer: Watermarking is used in streaming data processing to handle event time. It represents the progress of event time and determines when all data for a window has arrived.
9. What is the difference between Apache Beam’s batch and streaming processing modes?
Answer: In batch processing, data is processed as a bounded set, while streaming processing deals with unbounded, continuously arriving data.
10. What is the purpose of ParDo in Apache Beam?
Answer: ParDo is a fundamental transformation in Apache Beam that applies a user-defined function to each element in a collection, producing zero or more output elements.
11. What is the role of Apache Beam’s combined transformation?
Answer: Combine transforms are used to perform aggregations, such as sum or average, on elements within a window.
12. How does Apache Beam handle late data in streaming pipelines?
Answer: Apache Beam allows you to specify the allowed lateness for Windows so that late data can still be included in the processing. Late data is assigned to the appropriate window based on its event time.
13. What is the significance of the Apache Beam model’s DoFn concept?
Answer: DoFn represents a user-defined function that can be applied to elements in a collection. It encapsulates the processing logic for each element.
14. How does Apache Beam handle out-of-order data in streaming pipelines?
Answer: Apache Beam uses event time and watermarks to handle out-of-order data. Watermarks track the progress of event time, and elements arriving after the watermark are considered late.
15. Can you explain the concept of windowing functions in Apache Beam?
Answer: Windowing functions define how data is divided into windows for processing. They determine the size, placement, and overlap of windows.
16. What are the different types of triggers available in Apache Beam?
Answer: Apache Beam supports various triggers, including processing-time triggers, event-time triggers, and custom triggers. Triggers control when the accumulated data within a window is emitted for processing.
17. How can you perform key-based aggregations in Apache Beam?
Answer: You can use the GroupByKey transform followed by a Combine transform to perform key-based aggregations in Apache Beam.
18. What is the purpose of Apache Beam’s Flatten transform?
Answer: The Flatten transform is used to merge multiple PCollections into a single PCollection, allowing parallel processing of independent inputs.
19. What is the significance of the Apache Beam schema and how is it used?
Answer: The Apache Beam schema defines the structure of the data being processed. It can be used to enforce data types, perform schema evolution, and improve interoperability.
20. What is the command to change the default Listen port?
Answer: We can give a command like this Listen 9.126.8.139:8000. This command will change the default listen port and make the listening port is 8000.
Let us move to the next Apache Interview Questions.
21. What is the name of the WebLogic module?
Answer: WebLogic module name is so.
22. What is the log level of Apache?
Answer: The log level is: debug, info, warn, notice, crit, alarm, emerg, and error.
23. How will you kill the Apache process?
Answer: We can use the below command:
Kill $PIDNUMBER
24. What do you mean by these error codes 200, 403, and 503?
Answer: 200 – the server is ok.
403 – The server is trying to access the restricted file.
503 – The server is busy.
25. How you will check the httpd.conf consistency?
Answer: By giving the below command:
httpd -t
