Databricks Data Engineer Associate Question 448
Select 3A Data Engineer is working on a Databricks job that processes data from a Delta table and writes the results to another Delta table. The job fails during execution, and the error message in the task details mentions 'NullPointerException' and points to a specific line of code. What steps should the Data Engineer take to debug and resolve the issue?
- A
Check the task's error logs in the Databricks job run details to identify the root cause of the NullPointerException.
- B
Verify the input Delta table schema and ensure all required columns are present and contain non-null values.
- C
Review the cluster's configuration and increase the driver memory to handle larger data volumes.
- D
Examine the line of code mentioned in the error message to determine if it improperly handles null values in the input data.
- E
Optimize the job's performance by enabling Adaptive Query Execution (AQE) in the Spark configuration.
Show answer and explanation
Correct answers: A, B, D
Explanation
To debug a task failure caused by a NullPointerException, the Data Engineer should focus on identifying the root cause using error logs, validating the input Delta table schema and data, and reviewing the specific line of code mentioned in the error to ensure proper handling of null values. Increasing driver memory or enabling AQE are unrelated actions for resolving this specific issue.
- A. Correct.
Correct: Checking the error logs in the Databricks job run details is critical to understanding the exact cause of the NullPointerException.
- B. Correct.
Correct: If the input Delta table contains null values in columns that the code does not handle properly, it could lead to a NullPointerException. Verifying the schema and data is essential.
- C. Incorrect.
Incorrect: While increasing driver memory can help with memory-related issues, it is unrelated to debugging a NullPointerException.
- D. Correct.
Correct: The error message points to a specific line of code, so examining and fixing how null values are handled is a necessary step.
- E. Incorrect.
Incorrect: Enabling Adaptive Query Execution (AQE) can improve performance but does not directly address debugging a NullPointerException.