Understanding Elasticsearch: A Beginner’s Guide

Anurag Srivastava
3 min readMar 13


Elasticsearch is a search engine that is designed to help users quickly and easily find relevant information from large data sets. It is built on top of the Apache Lucene library and is commonly used for indexing, searching, and analyzing large amounts of data in real time. Here is a beginner’s guide to understanding Elasticsearch:

What is Elasticsearch used for?
Elasticsearch is commonly used for search and analytics use cases, such as log analytics, e-commerce search, website search, and security analytics. It can be used to search for structured or unstructured data and can be customized to meet specific use case requirements.

How does Elasticsearch work?
Elasticsearch is built on top of the Apache Lucene library, which provides low-level indexing and searching capabilities. Elasticsearch adds additional features and functionality on top of Lucene, such as distributed indexing and search, RESTful APIs, and real-time indexing and searching.

What are the key concepts of Elasticsearch?
Some key concepts to understand when working with Elasticsearch include:

  • Index: a collection of documents that have similar characteristics
  • Document: a basic unit of information in Elasticsearch that is stored in JSON format
  • Shard: a portion of an index that is stored on a single node in a cluster
  • Node: a single server that is part of an Elasticsearch cluster
  • Cluster: a collection of nodes that work together to store and index data

How do you install and set up Elasticsearch?
Elasticsearch can be installed on Windows, macOS, or Linux operating systems. The installation process involves downloading the Elasticsearch package, extracting it, and running Elasticsearch from the command line. Once Elasticsearch is installed, it can be configured through the elasticsearch.yml configuration file.

How do you query Elasticsearch?
Elasticsearch can be queried through a RESTful API using HTTP requests. Some common query types include:

  • Match query: searches for a specific value in a field
  • Term query: searches for exact matches in a field
  • Range query: searches for values within a specific range
  • Bool query: combines multiple queries with Boolean logic

What are some best practices for using Elasticsearch?
Some best practices for using Elasticsearch include:

  • Index only the data that you need to search
  • Use shards and replicas to distribute data across multiple nodes
  • Tune the cluster settings to optimize performance for your use case
  • Monitor the cluster to ensure that it is functioning correctly and to identify any issues or performance bottlenecks.

These are some of the basics of Elasticsearch. Overall, Elasticsearch is a powerful tool for search and analytics that provides a range of features and capabilities. Whether you’re working with large volumes of data, performing real-time search and analytics, or building a custom application, Elasticsearch can help you to extract valuable insights and make better decisions based on your data.

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If you found this article interesting, then you can explore “Mastering Kibana 6.0”, “Kibana 7 Quick Start Guide”, “Learning Kibana 7”, and “Elasticsearch 7 Quick Start Guide” books to get more insight about Elastic Stack, how to perform data analysis, and how you can create dashboards for key performance indicators using Kibana.

Other Blogs:
Introduction to Logstash
Introduction to Kibana
Log analysis with Elastic Stack
Introduction to OpenAPI Specification
Geo distance search using Elasticsearch
Loading CSV Data into Elasticsearch
Configure SonarQube Scanner with Jenkins
Configuring Logstash to Send MongoDB Data into Elasticsearch



Anurag Srivastava

Author of “Mastering Kibana6.x”, “Kibana7 Quick Start Guide”, “Learning Kibana7”, &“Elasticsearch7 Quick Start Guide” books & AWS Certified Solutions Architect.