- Data Structures and Algorithms: Familiarity with lists, dictionaries (hash maps), sorting algorithms, and data partitioning techniques.
- Concurrency and Parallelism: Understanding multithreading or multiprocessing to handle parallel tasks efficiently.
- Networking Basics: Knowledge of socket programming for inter-process communication over a network.
- Process Communication: Grasp how different processes communicate, coordinate, and handle synchronization issues.
- Fault Tolerance: Basic strategies to handle node failures and ensure data consistency.
- Serialization/Deserialization: Ability to convert data structures into a format suitable for transmission and reconstruct them afterward.
- Debugging Distributed Applications: Techniques for diagnosing and fixing issues that arise in a distributed environment.
- Resource Management: Understanding how to manage computational resources like CPU, memory, and network bandwidth.
- Python: Highly recommended for its simplicity and extensive standard libraries. Modules like multiprocessing, threading, and socket are useful.
- Go (Golang): Excellent support for concurrency with goroutines and channels, and it’s straightforward to use for networking tasks.
- Java: If you’re comfortable with it, since Hadoop (an open-source implementation of MapReduce) is written in Java.
- Python Standard Libraries:
- multiprocessing for parallel execution.
- socket for networking.
- pickle or json for serialization.
- Networking Tools:
- ZeroMQ or RabbitMQ for message queuing (optional, might add complexity).
- Development Tools:
- Docker: To simulate multiple nodes on a single machine.
- Virtual Environments: For isolated development spaces.
- Understand the MapReduce Model:
- Map Function: Processes input key-value pairs to generate intermediate key-value pairs.
- Reduce Function: Merges all intermediate values associated with the same intermediate key.
- Design the Architecture:
- Master Node:
- Splits the input data into chunks.
- Assigns Map tasks to worker nodes.
- Collects intermediate results and assigns Reduce tasks.
- Worker Nodes:
- Perform Map tasks on received data chunks.
- Send intermediate results back to the master or directly to Reduce workers.
- Perform Reduce tasks to produce final output.
- Implement the Components:
- Data Splitting: Divide the input data into manageable chunks.
- Task Scheduling: Master node assigns tasks to workers and monitors their progress.
- Communication Protocol: Define how nodes will communicate (e.g., using TCP sockets).
- Data Shuffling: Implement a mechanism to group intermediate data by keys before reducing.
- Handle Fault Tolerance (Optional for Simplicity):
- Retry Mechanism: If a worker fails, the master reassigns the task.
- Heartbeat Messages: Workers periodically send status updates to the master.
- Test with Simple Applications:
- Word Count: A classic MapReduce problem that’s easy to implement and test.
- Distributed Grep: Search for patterns in data across multiple nodes.
- Start Small: Begin with a single-machine version using multithreading before moving to a distributed setup.
- Incremental Development: Build and test each component individually before integrating them.
- Logging and Monitoring: Implement logging to help trace the flow of data and identify issues.
- Code Readability: Write clean, well-documented code to make debugging and future modifications easier.
- “MapReduce: Simplified Data Processing on Large Clusters” by Jeffrey Dean and Sanjay Ghemawat.
- MIT OpenCourseWare: Courses on distributed systems and parallel computing.