Elasticsearch Interview Questions and Answers

Last updated on Feb 06, 2023
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Elasticsearch Interview Questions

Elasticsearch is a real-time and evenly distributed search engine that supports RESTful searching and analysis based upon the Apache Lucene full-text search engine. It has distributed and full-field real-time analytics storage. Along with Logstash and Kibana, Elasticsearch is widely used. In the field of Elasticsearch during the last few years, ’ maximum competition is created. Hence, it becomes mandatory to know the most common Elasticsearch interview questions if you are willing to build a career in this segment. Elasticsearch is broadly used by major platforms. Most important among them are Wikipedia, Netflix, IFTTT, Accenture, Hip chat, Fujitsu, Stack Overflow, and Medium.

Elasticsearch is also document-oriented enables the storage of data and then their indexing so that the content becomes easily searchable. Elasticsearch entirely works over the HTTP interface and JSON documents, and altogether it is developed in Java programming language. It is known that the Elasticsearch server uses the port range around 9200 to 9300. In order to check if the server is running, you just need to type the URL of any corresponding homepage which is primarily followed in reference to the port number. Looking for a reliable piece of information, take a follow-up through these Elasticsearch interview questions.

About Elasticsearch

It is built upon Apache Lucene a full-text search engine
Document orientation stores the data which are structured JSON documents
Text support it supports full-text search indexing to provide faster results
Supports it supports auto-completion and instant results.
APIs Elasticsearch supports restful APIs for the retrieval of data and records
Serves Elasticsearch search the cross-platform
Developed and written in it is developed in Java language
License Apache license 2.0
Developed by Shay Banon
Elasticsearch is also an open source software

Most Frequently Asked Elasticsearch Interview Questions

Here in this article, we will be listing frequently asked Elasticsearch Interview Questions and Answers with the belief that they will be helpful for you to gain higher marks. Also, to let you know that this article has been written under the guidance of industry professionals and covered all the current competencies.

Q1. How to create a node in Elasticsearch?

In Elasticsearch, the nodes are added to enhance the quality and reliability of the cluster. There can be of the master node to control the entire cluster and also a basic data node. In order to add a node follows the steps-

  • You have to set up a new Elasticsearch instance
  • Specify its name in the cluster.name attribute
  • Begin the Elasticsearch and node will be created

Note: This is one of the basic Elasticsearch interview questions but an important one.

Q2. What is a split brain problem in Elasticsearch?

Split brain is a consequence that generates when the master nodes in the cluster fail. In the bunch of clusters if any master node fails, then the slave node can choose a new master note for the effective functionality. In case the former one gets restore or comes into the functioning again, then it leads to the conflict. This problem also rises when communication is failed among the nodes.

Q3. What is an Elasticsearch query? Explain the types of queries?

Elasticsearch has its own query domain where the queries can be defined in the JSON format. Elasticsearch serves domain specific language DSL queries that make it easy to resolve real-world queries. Broadly Elasticsearch is divided into the following two different types of queries which ultimately solve multiple other queries associated with them. The list of them is-

  • Full-text queries - this includes the multi-match query, match phrase prefix query, match query, common terms query and many more
  • Term level queries - this includes the term query, term set query, existing query, ids query, wildcard query, and lot more.
Q4. What is a Type in Elasticsearch?

In Elasticsearch, Type signifies the class of similar data. It can signify a name for making and is beneficial for the abstractions or for indicating the similar yet not identical data.

Q5. What is a cluster in Elasticsearch?

Cluster is a collection of one or multiple servers which consists of the data and also serves the federated indexing across all the different nodes. By default, a cluster can be identified by a significant name, i.e., Elasticsearch.

Q6. What are the advantages of Elasticsearch?

Being the open source and highly distributive network Elasticsearch has many advantages.

  • It is a document-oriented platform
  • Elasticsearch supports multiple search options
  • A large number of complicated queries can be executed speedily with Elasticsearch
  • In order to avoid the chance of data loss, Elasticsearch manages the record.
  • Elasticsearch also supports indexing and multi-tenancy
Q7. What is Elasticsearch? How does it work?

Elasticsearch is a full-text searchable engine which is based on Lucerne. Generally, Elasticsearch was released as an open source platform which was developed in JavaScript under the Apache license terms. Using the phrase "multi-tenant and capable full-text search," Elasticsearch can be justified shortly. It has an HTTP interface for web and schema-free JSON files. As it is developed in Javascript, it can index the documents in variedly diverse formats.

Elasticsearch promotes the indexing of documents targeting the repository. Elasticsearch stores and executes the data as it converts the initial form of files into the internal documents and secures them with the basic data structure resembling with the JSON objects.

Q8. How to install elasticsearch on windows?

Below mentioned are a few steps to install Elasticsearch in windows -

  • Download the zip file from relevant sources(websites)
  • Install it and launch through GUI
  • Carefully select the configuration and logs directories
  • Now choose to install it as service or manually
  • Finish the configuration steps carefully; it will be followed as cluster name, node, etc
  • Select the plug-in
Q9. What is the ingest node in Elasticsearch?

In Elasticsearch, an ingest node is a type of note that can be utilized during the documentation process before indexing. It is a part of the Elasticsearch cluster, and it intercepts the index request and bulk applying the transformation and later passes it back to the index.

Q10. What is a quorum in Elasticsearch?

The quorum by default, is set to action.write_onsistency. in case the quorum is not fulfilled then the index returns after the timeout with an error. Elasticsearch documentation follows the rule for write_consiatency level in quorum as quorum(>replicas/2+1).

After these basic details on Elasticsearch, let’s move to the Elasticsearch interview questions and their answers.


Using the common interface with JSON and HTTP, Shay Banon authored Elasticsearch in Java programming language. In February 2010, Elastic NV developed a stable version of Elaticsearch. Currently, version 7.1.1 is in the market which was released on May 28, 2019.

  • Elasticsearch is compatible with any platform
  • It is a Near real-time (NRT) which makes it easily searchable
  • The cluster of Elasticsearch is evenly distributed, which increase its scalability.
  • It supports multiple documents
  • Elasticsearch efficiently deals with the managed documents
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