Book Image

Building Big Data Pipelines with Apache Beam

By : Jan Lukavský
Book Image

Building Big Data Pipelines with Apache Beam

By: Jan Lukavský

Overview of this book

Apache Beam is an open source unified programming model for implementing and executing data processing pipelines, including Extract, Transform, and Load (ETL), batch, and stream processing. This book will help you to confidently build data processing pipelines with Apache Beam. You’ll start with an overview of Apache Beam and understand how to use it to implement basic pipelines. You’ll also learn how to test and run the pipelines efficiently. As you progress, you’ll explore how to structure your code for reusability and also use various Domain Specific Languages (DSLs). Later chapters will show you how to use schemas and query your data using (streaming) SQL. Finally, you’ll understand advanced Apache Beam concepts, such as implementing your own I/O connectors. By the end of this book, you’ll have gained a deep understanding of the Apache Beam model and be able to apply it to solve problems.
Table of Contents (13 chapters)
1
Section 1 Apache Beam: Essentials
5
Section 2 Apache Beam: Toward Improving Usability
9
Section 3 Apache Beam: Advanced Concepts

Implementing our first streaming pipeline using SQL

We will follow the same path that we walked when we started playing with the Java SDK of Apache Beam. The very first pipeline we implemented, which was in Chapter 1, Introducing Data Processing with Apache Beam, was a pipeline that read input from a resource file named lorem.txt. Our goal was to process this file and output the number of occurrences of words within that file. So, let's see how our solution would differ if we used SQL to solve it!

We have implemented the equivalent of com.packtpub.beam.chapter1.FirstPipeline in com.packtpub.beam.chapter5.FirstSQLPipeline. The main differences are summarized here:

  1. First, we need to create a Schema that will represent our input. The input is raw lines of text as String objects, so a possible Schema representing it is a single-field Schema defined as follows:
    Schema lineSchema = Schema.of(
        Field.of("s", FieldType.STRING));
  2. We then attach...