Book Image

Apache Spark 2: Data Processing and Real-Time Analytics

By : Romeo Kienzler, Md. Rezaul Karim, Sridhar Alla, Siamak Amirghodsi, Meenakshi Rajendran, Broderick Hall, Shuen Mei
Book Image

Apache Spark 2: Data Processing and Real-Time Analytics

By: Romeo Kienzler, Md. Rezaul Karim, Sridhar Alla, Siamak Amirghodsi, Meenakshi Rajendran, Broderick Hall, Shuen Mei

Overview of this book

Apache Spark is an in-memory, cluster-based data processing system that provides a wide range of functionalities such as big data processing, analytics, machine learning, and more. With this Learning Path, you can take your knowledge of Apache Spark to the next level by learning how to expand Spark's functionality and building your own data flow and machine learning programs on this platform. You will work with the different modules in Apache Spark, such as interactive querying with Spark SQL, using DataFrames and datasets, implementing streaming analytics with Spark Streaming, and applying machine learning and deep learning techniques on Spark using MLlib and various external tools. By the end of this elaborately designed Learning Path, you will have all the knowledge you need to master Apache Spark, and build your own big data processing and analytics pipeline quickly and without any hassle. This Learning Path includes content from the following Packt products: • Mastering Apache Spark 2.x by Romeo Kienzler • Scala and Spark for Big Data Analytics by Md. Rezaul Karim, Sridhar Alla • Apache Spark 2.x Machine Learning Cookbook by Siamak Amirghodsi, Meenakshi Rajendran, Broderick Hall, Shuen MeiCookbook
Table of Contents (23 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
Index

Debugging Spark applications


In this section, we will see how to debug Spark applications that are running locally (on Eclipse or IntelliJ), standalone or cluster mode in YARN or Mesos. However, before diving deeper, it is necessary to know about logging in the Spark application.

Logging with log4j with Spark recap

As stated earlier, Spark uses log4j for its own logging. If you configured Spark properly, Spark gets logged all the operation to the shell console. A sample snapshot of the file can be seen from the following figure:

Figure 16: A snap of the log4j.properties file

Set the default spark-shell log level to WARN. When running the spark-shell, the log level for this class is used to overwrite the root logger's log level so that the user can have different defaults for the shell and regular Spark apps. We also need to append JVM arguments when launching a job executed by an executor and managed by the driver. For this, you should edit the conf/spark-defaults.conf. In short, the following...