Top 50 Elasticsearch Interview Questions and Answers

Explain in brief about Elasticsearch? Elasticsearch Apache Lucene search engine is a database that stores retrieve and manages document-oriented and semi-structured data. It provides real-time search and analytics for structured…

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Top 50 Interview Questions and Answers of Elastisearch

Short description about: Elasticsearch is a distributed, free and open search and analytics engine for all types of data, including textual, numerical, geospatial, structured, and unstructured. Elasticsearch is built on…

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Top Elastic search interview questions and answers

What is the main use of Elasticsearch? Elasticsearch is used for a lot of different use cases: “classical” full-text search, analytics store, auto-completer, spell checker, alerting engine, and as a…

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Elasticsearch Cluster Setup and Configuration Tutorial step by step using AWS ec2

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Elasticsearch QUERY Parameters Examples with Explanation

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elasticsearch-plugin

How to use elastic search EC2 discovery plugin?

Problem To increase the performance in Elasticsearch, many times we add new nodes to Elasticsearch cluster and manually change the configuration file with new IP address, etc. so that it…

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elasticsearch-error-node

Elastic Search Error – Node is started with node.data=false, but has shard data

[2019-07-11T09:59:18,013][ERROR][o.e.b.Bootstrap ] [es-master01] Exception java.lang.IllegalStateException: Node is started with node.data=false, but has shard data: [/home/ec2-user/elasticsearch-7.2.0/data/nodes/0/indices/6XsNftnbSbOnzPK3wOKc 0w/0]. Use ‘elasticsearch-node repurpose’ tool to clean up at org.elasticsearch.env.NodeEnvironment.ensureNoShardData(NodeEnvironment.java:1065) ~[elasticsearch-7.2.0.jar:7.2.0] at org.elasticsearch.env.NodeEnvironment.(NodeEnvironment.java:324) ~[elasticsearch-7.2.0.jar:7.2.0] Solution

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elastic-search-error-max-virtual-memory-areas

Elastic Search Error – max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

Errors [2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144] Solution To make it persistent, you can add this line: $ sudo vi /etc/sysctl.conf…

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elastic-search-error-max-max-file-descriptors

Elastic Search Error – max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]

Elastic Search Error – max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535] Solution Temporary to the current login session To set ulimit value…

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sample-data-elastic-search

How to create sample data to perform searches using elastic search?

Step 1 – Go to: http://www.json-generator.com/ Step 2 – Download and save as customers_full.json Step 3 – Open customers_full.json in sublimetext Remove the array brackets Find-Replace },{ with }\n{ in…

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elasticsearch-error-bulk-request

Elastic Search Error – The bulk request must be terminated by a newline

FIX – Add a New line in customers_full.json

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elasticsearch-error-illegal

ElasticSearch Error – illegal_argument_exception – Rejecting mapping update to type

########### COMMAND ################# ########### OUTPUT ########### Solution Multiple mapping types are not supported in indices created in 6.0 The ability to have multiple mapping types per index has been removed…

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elasticsearch-error-content-type-header

ElasticSearch Error – Content-Type header [application/x-www-form-urlencoded] is not supported

To fix this, add curl option -H ‘Content-Type: application/json’. This error is due to strict content-type checking introduced in ElasticSearch 6.0 Solution

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Understanding the Update API in Elasticsearch

The update API allows to update(also allows to delete, or ignore the operation). a document based on a script provided. The operation gets the document from the index, runs the…

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Understanding Elasticsearch Index Mapping & Schema

A schema is a description of one or more fields that describes the document type and how to handle the different fields of a document. The schema in Elasticsearch is…

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Find out elastic Search health using _cat/health

To check elasticsearch cluster health by using (CURL) and Cluster API “cat” provieded by elasticsearch The cat API print the info in JSON format, compact and aligned text which is…

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Understanding Elasticsearch Keywords and Terminology

Understanding Elasticsearch Keywords and Terminology Elasticsearch Terminology Description Cluster “A cluster is a collection of one or more nodes (servers) that together holds your entire data and provides federated indexing…

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Crash Course of Elasticsearch in 10 mins

What is Elasticsearch? Elasticsearch is fast, horizontally scalable open source search engine. It provides HTTP API for storing and indexing JSON documents and with default configuration it behaves a little…

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Elasticsearch Web References & Cheatsheet

Elasticsearch official documentation https://www.elastic.co/guide/en/elasticsearch/reference/6.x/index.html Very good Elasticsearch Guide on Github https://github.com/dzharii/awesome-elasticsearch Elasticsearch Official forum https://discuss.elastic.co/ Stackoverflow elasticsearch handlers http://stackoverflow.com/questions/tagged/elasticsearch Jolicode elasticsearch Cheatsheet http://elasticsearch-cheatsheet.jolicode.com/ Elasticsearch DevOpsSchool reference https://www.devopsschool.com/blog/category/elastic-stack/ https://www.devopsschool.com/tutorial/elastic/

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Web GUI tools for Elasticsearch cluster

elasticsearch-head is a web front end for browsing and interacting with an Elastic Search cluster. There are multiple ways of running elasticsearch-head. Running as a plugin of ElasticSearch (this is…

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