OpenSearch: The Complete Guide to Distributed Search and Analytics

Introduction

OpenSearch is a distributed, RESTful search and analytics engine built on Apache Lucene. Originally forked from Elasticsearch in 2021, OpenSearch provides powerful full-text search capabilities, real-time analytics, and visualization tools. In 2026, OpenSearch continues to evolve as a leading open-source search platform.

This comprehensive guide covers everything you need to get started with OpenSearch.

What is OpenSearch?

OpenSearch is a distributed search engine that provides:

Full-Text Search: Powerful text matching with relevance scoring
Real-Time Analytics: Aggregate and analyze data in near real-time
Distributed Architecture: Scale horizontally across clusters
RESTful API: Easy HTTP-based interactions
Visualization: Built-in dashboards with OpenSearch Dashboards

OpenSearch vs Elasticsearch

Feature	OpenSearch	Elasticsearch
License	Apache 2.0	SSPL
Governance	AWS/OpenSearch Community	Elastic
Security	Built-in	XPack (paid)
Visualization	OpenSearch Dashboards	Kibana (paid features)

Installation

Docker Installation

# Start OpenSearch
docker run -d --name opensearch \
  -p 9200:9200 \
  -p 9600:9600 \
  -e "discovery.type=single-node" \
  -e "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m" \
  opensearchproject/opensearch:latest

# Start OpenSearch Dashboards
docker run -d --name opensearch-dashboards \
  -p 5601:5601 \
  -e OPENSEARCH_HOSTS=https://opensearch:9200 \
  opensearchproject/opensearch-dashboards:latest

OpenSearch DSL Basics

Creating Indexes

PUT /products
{
  "settings": {
    "number_of_shards": 3,
    "number_of_replicas": 1
  },
  "mappings": {
    "properties": {
      "name": { "type": "text" },
      "price": { "type": "float" },
      "category": { "type": "keyword" },
      "in_stock": { "type": "boolean" },
      "created_at": { "type": "date" }
    }
  }
}

Document Operations

# Index a document
POST /products/_doc
{
  "name": "Wireless Mouse",
  "price": 29.99,
  "category": "Electronics",
  "in_stock": true,
  "created_at": "2026-03-05T10:00:00Z"
}

# Get a document
GET /products/_doc/1

# Update
POST /products/_update/1
{ "doc": { "price": 24.99 } }

# Delete
DELETE /products/_doc/1

Search Queries

# Match all
GET /products/_search
{ "query": { "match_all": {} } }

# Full-text search
GET /products/_search
{ "query": { "match": { "name": "wireless mouse" } } }

# Exact match
GET /products/_search
{ "query": { "term": { "category": "Electronics" } } }

# Bool query
GET /products/_search
{
  "query": {
    "bool": {
      "must": [{ "match": { "name": "mouse" } }],
      "filter": [
        { "term": { "in_stock": true } },
        { "range": { "price": { "lte": 50 } } }
      ]
    }
  }
}

Aggregations

# Terms aggregation
GET /products/_search
{
  "size": 0,
  "aggs": {
    "categories": { "terms": { "field": "category" } }
  }
}

# Average
GET /products/_search
{
  "size": 0,
  "aggs": {
    "avg_price": { "avg": { "field": "price" } }
  }
}

Data Types

Core Types

{
  "properties": {
    "text_field": { "type": "text" },
    "keyword_field": { "type": "keyword" },
    "int_field": { "type": "integer" },
    "long_field": { "type": "long" },
    "float_field": { "type": "float" },
    "bool_field": { "type": "boolean" },
    "date_field": { "type": "date" },
    "geo_field": { "type": "geo_point" }
  }
}

Python Integration

from opensearchpy import OpenSearch

client = OpenSearch(
    hosts=[{'host': 'localhost', 'port': 9200}]
)

# Create index
client.indices.create(
    index='products',
    body={
        'mappings': {
            'properties': {
                'name': {'type': 'text'},
                'price': {'type': 'float'}
            }
        }
    }
)

# Index document
client.index(index='products', body={'name': 'Mouse', 'price': 29.99})

# Search
response = client.search(
    index='products',
    body={'query': {'match': {'name': 'mouse'}}}
)

Conclusion

OpenSearch provides powerful search and analytics with a RESTful API. Understanding OpenSearch DSL enables building sophisticated search applications.