Book Image

Mastering Apache Storm

By : Ankit Jain
Book Image

Mastering Apache Storm

By: Ankit Jain

Overview of this book

Apache Storm is a real-time Big Data processing framework that processes large amounts of data reliably, guaranteeing that every message will be processed. Storm allows you to scale your data as it grows, making it an excellent platform to solve your big data problems. This extensive guide will help you understand right from the basics to the advanced topics of Storm. The book begins with a detailed introduction to real-time processing and where Storm fits in to solve these problems. You’ll get an understanding of deploying Storm on clusters by writing a basic Storm Hello World example. Next we’ll introduce you to Trident and you’ll get a clear understanding of how you can develop and deploy a trident topology. We cover topics such as monitoring, Storm Parallelism, scheduler and log processing, in a very easy to understand manner. You will also learn how to integrate Storm with other well-known Big Data technologies such as HBase, Redis, Kafka, and Hadoop to realize the full potential of Storm. With real-world examples and clear explanations, this book will ensure you will have a thorough mastery of Apache Storm. You will be able to use this knowledge to develop efficient, distributed real-time applications to cater to your business needs.
Table of Contents (19 chapters)
Title Page
About the Author
About the Reviewers
Customer Feedback

Writing Trident functions, filters, and projections

This section covers the definition of Trident functions, filters, and projections. Trident functions, filters, and projections are used to modify/filter the input tuples based on certain criteria. This section also covers how we can write Trident functions, filters, and projections.

Trident function

Trident functions contain logic to modify the original tuple. A Trident function gets a set of fields of the tuple as input and emits one or more tuples as output. The fields of the output tuples are merged with the fields of the input tuple to form the complete tuple, which will pass to the next action in the topology. If the Trident function emits no tuples corresponding to the input tuple, then that tuple is removed from the stream.

We can write a custom Trident function by extending the storm.trident.operation.BaseFunction class and implementing the execute(TridentTuple tuple, TridentCollector collector) method.

Let's write the sample Trident...