Book Image

Learning Apache Flink

By : Tanmay Deshpande
Book Image

Learning Apache Flink

By: Tanmay Deshpande

Overview of this book

<p>With the advent of massive computer systems, organizations in different domains generate large amounts of data on a real-time basis. The latest entrant to big data processing, Apache Flink, is designed to process continuous streams of data at a lightning fast pace.</p> <p>This book will be your definitive guide to batch and stream data processing with Apache Flink. The book begins with introducing the Apache Flink ecosystem, setting it up and using the DataSet and DataStream API for processing batch and streaming datasets. Bringing the power of SQL to Flink, this book will then explore the Table API for querying and manipulating data. In the latter half of the book, readers will get to learn the remaining ecosystem of Apache Flink to achieve complex tasks such as event processing, machine learning, and graph processing. The final part of the book would consist of topics such as scaling Flink solutions, performance optimization and integrating Flink with other tools such as ElasticSearch.</p> <p>Whether you want to dive deeper into Apache Flink, or want to investigate how to get more out of this powerful technology, you’ll find everything you need inside.</p>
Table of Contents (17 chapters)
Learning Apache Flink
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Logging best practices


It is very important to have logs configured in any software application. Logs help in debugging the issues.  We don’t follow these logging practices, it would be very diffuclt to understand the progress of the job or if any issues with it. There are couple of libraries we can use for better logging experience.  

Configuring Log4j

Log4j, as we know, is one the most widely used logging libraries. We can configure it in any Flink application with very little effort. We have only to include a log4j.properties file. We can pass the log4j.properties file by passing it as an Dlog4j.configuration=/path/to/log4j.properties argument.

Flink supports the following default property files:

  • log4j-cli.properties: This file is used by the Flink command line tool. Here is the exact file at https://github.com/apache/flink/blob/master/flink-dist/src/main/flink-bin/conf/log4j-cli.properties.

  • log4j-yarn-session.properties: This file is used by the Flink YARN session. Here is the exact file...