Book Image

Monitoring Elasticsearch

By : Dan Noble, Pulkit Agrawal, Mahmoud Lababidi
Book Image

Monitoring Elasticsearch

By: Dan Noble, Pulkit Agrawal, Mahmoud Lababidi

Overview of this book

ElasticSearch is a distributed search server similar to Apache Solr with a focus on large datasets, a schema-less setup, and high availability. This schema-free architecture allows ElasticSearch to index and search unstructured content, making it perfectly suited for both small projects and large big data warehouses with petabytes of unstructured data. This book is your toolkit to teach you how to keep your cluster in good health, and show you how to diagnose and treat unexpected issues along the way. You will start by getting introduced to ElasticSearch, and look at some common performance issues that pop up when using the system. You will then see how to install and configure ElasticSearch and the ElasticSearch monitoring plugins. Then, you will proceed to install and use the Marvel dashboard to monitor ElasticSearch. You will find out how to troubleshoot some of the common performance and reliability issues that come up when using ElasticSearch. Finally, you will analyze your cluster’s historical performance, and get to know how to get to the bottom of and recover from system failures. This book will guide you through several monitoring tools, and utilizes real-world cases and dilemmas faced when using ElasticSearch, showing you how to solve them simply, quickly, and cleanly.
Table of Contents (15 chapters)
Monitoring Elasticsearch
About the Author
About the Reviewers

Diagnosing problems

Elasticsearch node failures can manifest in many different ways. Some of the symptoms of node failures are as follows:

  • A node crashes during heavy data indexing

  • Elasticsearch process stops running for an unknown reason

  • A cluster won't recover from a yellow or red state

  • Query requests time out

  • Index requests time out

When a node in your cluster experiences problems such as these, it can be tempting to just restart Elasticsearch or the node itself and move on like nothing happened. However, without addressing the underlying issue, the problem is likely to resurface in the future. If you encounter scenarios such as the ones just listed, check the health of your cluster in the following manner:

  • Check the cluster health with Elasticsearch-head or Kopf

  • Check the historical health with Marvel

  • Check for Nagios alerts

  • Check Elasticsearch log files

  • Check system log files

  • Check the system health using command-line tools

These steps will help diagnose the root cause of problems in your cluster...