Book Image

Essential PySpark for Scalable Data Analytics

By : Sreeram Nudurupati
Book Image

Essential PySpark for Scalable Data Analytics

By: Sreeram Nudurupati

Overview of this book

Apache Spark is a unified data analytics engine designed to process huge volumes of data quickly and efficiently. PySpark is Apache Spark's Python language API, which offers Python developers an easy-to-use scalable data analytics framework. Essential PySpark for Scalable Data Analytics starts by exploring the distributed computing paradigm and provides a high-level overview of Apache Spark. You'll begin your analytics journey with the data engineering process, learning how to perform data ingestion, cleansing, and integration at scale. This book helps you build real-time analytics pipelines that help you gain insights faster. You'll then discover methods for building cloud-based data lakes, and explore Delta Lake, which brings reliability to data lakes. The book also covers Data Lakehouse, an emerging paradigm, which combines the structure and performance of a data warehouse with the scalability of cloud-based data lakes. Later, you'll perform scalable data science and machine learning tasks using PySpark, such as data preparation, feature engineering, and model training and productionization. Finally, you'll learn ways to scale out standard Python ML libraries along with a new pandas API on top of PySpark called Koalas. By the end of this PySpark book, you'll be able to harness the power of PySpark to solve business problems.
Table of Contents (19 chapters)
1
Section 1: Data Engineering
6
Section 2: Data Science
13
Section 3: Data Analysis

Scaling out machine learning

In the previous sections, we learned that ML is a set of algorithms that, instead of being explicitly programmed, automatically learn patterns hidden within data. Thus, an ML algorithm exposed to a larger dataset can potentially result in a better-performing model. However, traditional ML algorithms were designed to be trained on a limited data sample and on a single machine at a time. This means that the existing ML libraries are not inherently scalable. One solution to this problem is to down-sample a larger dataset to fit in the memory of a single machine, but this also potentially means that the resulting models aren't as accurate as they could be.

Also, typically, several ML models are built on the same dataset, simply varying the parameters supplied to the algorithm. Out of these several models, the best model is chosen for production purposes, using a technique called hyperparameter tuning. Building several models using a single machine,...