[Solved] Find the mistake in this code snippet for merging small files into a SequenceFile: SequenceFile.Writer writer = SequenceFile.createWriter(conf, path, keyClass, valueClass); | Hadoop

Hadoop - Performance Tuning

Find the mistake in this code snippet for merging small files into a SequenceFile:

SequenceFile.Writer writer = SequenceFile.createWriter(conf, path, keyClass, valueClass);
for (File file : files) {
  writer.append(file.getName(), file);
}
writer.close();

AFile object cannot be used directly as value in append method

BWriter should not be closed after appending files

CFile names cannot be keys in SequenceFile

DNo mistake, code is correct

Step-by-Step Solution

Solution:

Step 1: Understand SequenceFile append method parameters
append expects Writable key and Writable value objects, not File objects.
Step 2: Identify why File object is incorrect
File is not Writable; file content should be read and converted to Writable type.
Final Answer:
File object cannot be used directly as value in append method -> Option A
Quick Check:
File must be converted to Writable before append [OK]

Quick Trick: Convert file content to Writable before append [OK]

Common Mistakes:

Closing writer too early is not an error here
Thinking file name cannot be key
Assuming code is correct as is

Master "Performance Tuning" in Hadoop

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Time

More Hadoop Quizzes

Find the mistake in this code snippet for merging small files into a SequenceFile:

Step 1: Understand SequenceFile append method parameters

Step 2: Identify why File object is incorrect

Final Answer:

Quick Check:

Want More Practice?