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

Case studies

This section offers some real-world problem scenarios and solutions to use Elasticsearch.

Node configuration

You have a five-node production cluster, where each node has 32GB of total memory and 16GB is allocated to Elasticsearch. Lately, you've noticed a problem: every couple of days, node-05 leaves the cluster without warning. Restarting Elasticsearch on this node solves the problem temporarily, but the node will drop out of the cluster again in a few days. How do we go about looking into this issue?

The next time this error happens, check the Elasticsearch logs before restarting the node:

tail -n 500  /var/log/elasticsearch/*.log

You notice in the log file that Elasticsearch is throwing an OutOfMemoryError exception, like the following:

Caused by: java.lang.OutOfMemoryError: Java heap space
        at org.apache.lucene.util.fst.FST.<init>(
        at org.apache.lucene.util.fst.FST.&lt...