Preface

Welcome to Monitoring Elasticsearch!

There are many books and online tutorials that cover the Elasticsearch API and how to configure a cluster. But, until now, there hasn't been a thorough, accessible resource for monitoring and troubleshooting purposes. We've found that Elasticsearch monitoring tools drastically improve our ability to solve cluster issues and greatly increase cluster reliability and performance as a result. We wrote this book to share those use cases and the insights that came out of them.

This book covers how to use several popular open source and commercial Elasticsearch monitoring tools, namely, Elasticsearch-head, Bigdesk, Marvel, Kopf, and Kibana. There's also a section on the Elasticsearch cat API and how to use Nagios to perform general system monitoring. Moreover, we will discuss several case studies with real-world examples of troubleshooting Elasticsearch issues using these tools.

We believe that the best way to learn is to do. In this book, we'll go over how to set up a sample Elasticsearch cluster and load it with data. At times, we'll deliberately introduce problems into the cluster so that we can see how the errors are tracked using our various monitoring tools. Following along with these examples in your own cluster will help you learn both how to use the monitoring tools and how to tackle new and unknown issues that may arise.

After reading this book, we hope that you will be better equipped to run and maintain an Elasticsearch cluster. You will also be more prepared to diagnose and solve cluster issues, such as a node going down, the Elasticsearch process dying, configuration errors, shard errors, OutOfMemoryError exceptions, slow queries, and slow indexing performance.