How are keys and values presented and passed to the reducers during a standard sort and shuffle phase of MapReduce?

• A. Keys are presented to reducer in sorted order; values for a given key are not sorted.
• B. Keys are presented to a reducer in random order; values for a given key are not sorted.
• C. Keys are presented to a reducer in random order; values for a given key are sorted in ascending order.
• D. Keys are presented to reducer in sorted order; values for a given key are sorted in ascending order.

You need to create a job that does frequency analysis on input data. You will do this by writing a Mapper that uses TextInputFormat and splits each value (a line of text from an input file) into individual characters. For each one of these characters, you will emit the character as a key and an InputWritable as the value. As this will produce proportionally more intermediate data than input data, which two resources should you expect to be bottlenecks?

• A. Processor and RAM
• B. Disk I/O and network I/O
• C. Processor and network I/O
• D. Processor and disk I/O

You have user profile records in your OLPT database, that you want to join with web logs you have already ingested into the Hadoop file system. How will you obtain these user records?

• A. Sqoop import
• B. Hive LOAD DATA command
• C. Ingest with Flume agents
• D. Ingest with Hadoop Streaming
• E. Pig LOAD command
• F. HDFS command

A client application creates an HDFS file named foo.txt with a replication factor of 3. Identify which best describes the file access rules in HDFS if the file has a single block that is stored on data nodes A, B and C?

• A. The file will be marked as corrupted if data node B fails during the creation of the file.
• B. Each data node stores a copy of the file in the local file system with the same name as the HDFS file.
• C. Each data node locks the local file to prohibit concurrent readers and writers of the file.
• D. The file can be accessed if at least one of the data nodes storing the file is available.