Distributed Machine Learning

M2: Distributed ML Algorithms

M2: Distributed ML Algorithms #

This module applies parallel and distributed computing to ML algorithms. It examines how to divide computation, combine results, and balance communication against useful work during training.

Module coverage:

  • Parallel ML Algorithms: CNNs, gradient descent and SGD, SVM, k-means, k-nearest neighbours, decision trees, and random forests.
  • Distributed Training Strategies: data parallelism, model parallelism, pipeline parallelism, gradient checkpointing, and mixed-precision training.

Learning Objectives #

  • Decompose ML algorithms into independent and dependent work.
  • Explain how local results are aggregated and where communication is required.
  • Compare distributed execution through Hadoop and Spark.
  • Choose training strategies that address compute and memory constraints.

Pages #

ChapterPageMain focus
4Parallelisation of ML AlgorithmsProblem decomposition, ensembles, XGBoost, k-means, trees, forests, and SVM
5Communication-Aware Distributed MLCommunication overhead, distributed k-means and k-NN, model parallelism, and SGD
6Clusters, Hadoop, and SparkCluster frameworks, MapReduce k-means, distributed CNNs, and communication reduction
7Distributed Training StrategiesData, model, and pipeline parallelism, checkpointing, and mixed precision

Topic Outline #

4. Parallelisation of ML Algorithms #

  • Problem decomposition and parallelisation
  • Ensemble methods and XGBoost on CPUs
  • k-means
  • Distributed decision trees and random forests
  • Distributed implementations using Spark ML and XGBoost
  • Parallel SVM kernel computation using block-wise and MapReduce-style methods

5. Communication-Aware Distributed ML #

  • Communication overhead in distributed algorithms
  • Distributed k-means and model parallelism
  • k-NN: data partitioning, locality-sensitive hashing, and distributed indexing
  • KD-tree and Ball-tree indexing versus brute-force MapReduce
  • Accuracy–latency trade-offs in approximate k-NN
  • Gradient descent and SGD: mini-batch, synchronous, and asynchronous variants

6. Clusters, Hadoop, and Spark #

  • Cluster computing with Hadoop and Spark
  • Lloyd’s k-means algorithm in MapReduce
  • Mini-batch k-means and streaming variants
  • Convergence criteria and communication reduction through compressed updates
  • CNN data and model parallelism, including layer splitting and tensor slicing
  • Mixed precision, pipeline parallelism, and distributed training frameworks

7. Distributed Training Strategies ☆ #

  • Data parallelism
  • Model parallelism
  • Pipeline parallelism
  • Gradient checkpointing
  • Mixed-precision training

How This Module Connects #

Use M1: Foundations to interpret complexity and speedup. Continue to M3: Scale-Out Systems for the platforms and communication mechanisms that support larger training runs.

Communication-Aware Distributed ML

Communication-Aware Distributed ML #

Distributed machine learning is effective only when saved computation exceeds the cost of moving data and synchronising workers. Algorithm design must therefore account for message size, message frequency, barriers, and parameter placement.

Course coverage:

  1. Communication overhead, illustrated through distributed k-means
  2. Model parallelism when parameters do not fit or compute must be divided
  3. Distributed k-nearest neighbours: partitioning, indexing, and approximate search
  4. Gradient descent, SGD, and mini-batch optimisation
  5. Synchronous versus asynchronous updates

Learning Objectives #

By the end of this page, you should be able to:

ML System Optimisation

ML System Optimisation #

ML System Optimisation studies how to make machine learning workloads faster, more scalable, more memory-efficient, and suitable for different hardware platforms.

The subject connects machine learning algorithms with the systems that train and deploy them: multi-core CPUs, GPUs, distributed clusters, cloud platforms, edge devices, and embedded systems.

ML system optimisation = model quality + computational efficiency + hardware awareness + scalability

The learning path begins with performance measurement and parallel computing, progresses through distributed machine learning and scale-out platforms, and concludes with model compression and resource-constrained deployment.