HDFS, MapReduce, Spark RDDs and DataFrames, lazy evaluation, partitioning, shuffles and Kafka streaming basics.
40 cards · basic cards · AI-written, checked twice. Edit anything.
- What is HDFS?
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Distributed file system designed for storing large files across clusters with high fault tolerance
- What is the NameNode in HDFS?
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Master node that manages the file system namespace and controls file access
- What is a DataNode in HDFS?
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Slave node that stores data blocks and performs block creation, deletion, and replication operations
- What is block replication in HDFS?
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Storing copies of data blocks on multiple nodes for redundancy and fault tolerance
- What is the default replication factor in HDFS?
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3
- How does HDFS achieve fault tolerance?
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Through block replication and automatic replication of blocks from failed nodes to healthy ones
- What is rack awareness in HDFS?
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The ability to optimize replica placement by understanding cluster topology and node locations
- What is MapReduce?
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Programming model for distributed processing that divides jobs into map and reduce phases
- What does the Map function do in MapReduce?
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Takes input data and produces intermediate key-value pairs
- What does the Reduce function do in MapReduce?
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Aggregates values associated with the same key from the mapper output
- What is the Shuffle and Sort phase in MapReduce?
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Process that sorts mapper output by key and groups values with identical keys for reducers
- What is data locality in MapReduce?
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Principle of processing data on the node where it is stored rather than moving data across the network
- What is a combiner in MapReduce?
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Mini-reducer that runs on mapper output to reduce data transferred to reducers
- What are InputFormats in MapReduce?
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Specify how input data is split and read, determining the number of mappers and data distribution
- What is an RDD in Spark?
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Immutable, distributed, fault-tolerant collection of objects that can be processed in parallel