Full-Text Search Overview and Elasticsearch Introduction with Installation Guide

Before discussing Elasticsearch, the article defines full‑text search as the process of scanning each word in a document, creating an index that records the word’s frequency and position, and then using that index to retrieve relevant documents when a query is issued.

Full‑text retrieval aims for comprehensive, accurate, and fast results, handling only text without semantic analysis, performing case‑insensitive searches in English, and ranking results by relevance.

Elasticsearch (ES) is introduced as an open‑source, enterprise‑grade search engine built on Apache Lucene. While Lucene offers high performance, its API is complex; Elasticsearch simplifies usage by providing a Java‑based RESTful API, abstracting Lucene’s intricacies.

The origin story describes Shay Banon’s early work on Lucene, the creation of the Compass project, and the evolution to Elasticsearch in February 2010, which quickly became one of the most popular projects on GitHub with over 300 contributors.

Installation

Traditional Installation

Prepare the environment: CentOS 7.x+, Ubuntu, Windows, or macOS with JDK 11+ (or JDK 8 with proper configuration).

Download ES from elastic.co .

Create a non‑root user for running ES.

Extract the package.

Inspect the directory structure (bin, config, data, jdk, lib, logs, modules, plugins).

Start the ES service.

Configure environment variables.

Restart ES.

Verify by accessing http://localhost:9200 (default port 9200).

Enable remote access by editing config/elasticsearch.yml and restarting.

Docker Installation

Pull the Elasticsearch image.

Run the container.

Access ES at http://127.0.0.1:9200/.