Elasticsearch is a powerful and scalable open-source search and analytics engine that is widely used for storing, searching, and analyzing large volumes of data. Whether you are a developer, system administrator, or data analyst, having a cheatsheet can be immensely helpful for quickly referencing essential Elasticsearch commands and configurations. In this blog, we will provide a comprehensive Elasticsearch cheatsheet with code snippets for easy reference.
Index Operations
Create an Index
PUT /index_name
Check if an Index Exists
HEAD /index_name
Delete an Index
DELETE /index_name
Document Operations
Index a Document
POST /index_name/_doc/document_id
{
"field1": "value1",
"field2": "value2"
}
Get a Document
GET /index_name/_doc/document_id
Update a Document
POST /index_name/_update/document_id
{
"doc": {
"field1": "new_value"
}
}
Delete a Document
DELETE /index_name/_doc/document_id
Querying
Simple Query
GET /index_name/_search?q=query_string
Match Query
GET /index_name/_search
{
"query": {
"match": {
"field": "query_string"
}
}
}
Term Query
GET /index_name/_search
{
"query": {
"term": {
"field": "value"
}
}
}
Aggregations
Terms Aggregation
GET /index_name/_search
{
"aggs": {
"agg_name": {
"terms": {
"field": "field_name"
}
}
}
}
Date Histogram Aggregation
GET /index_name/_search
{
"aggs": {
"agg_name": {
"date_histogram": {
"field": "date_field",
"calendar_interval": "day"
}
}
}
}
Mapping
Define Mapping
PUT /index_name
{
"mappings": {
"properties": {
"field_name": {
"type": "text"
}
}
}
}
Get Mapping
GET /index_name/_mapping
Cluster Health
Check Cluster Health
GET /_cat/health?v
Cluster Nodes
GET /_cat/nodes?v
This Elasticsearch cheatsheet covers essential operations for managing indices, documents, querying, aggregations, mapping, and monitoring cluster health. Bookmark this cheatsheet for quick reference and boost your productivity when working with Elasticsearch. Keep in mind that Elasticsearch is a versatile tool, and this cheatsheet provides only a glimpse of its capabilities. For more in-depth information, refer to the official Elasticsearch documentation.
FAQ
1. What is Elasticsearch?
Elasticsearch is an open-source search and analytics engine built on top of Apache Lucene. It is designed for distributed storage and retrieval of structured and unstructured data, making it a powerful tool for search and analysis.
2. How do I create an index in Elasticsearch?
To create an index in Elasticsearch, you can use the following HTTP request:PUT /index_name
This command creates an index with the specified name.
3. What is the difference between a “match” and a “term” query?
A “match” query is used for full-text search, analyzing the input and matching relevant documents, while a “term” query is used for exact matching of terms without analysis. “Match” is suitable for textual content, while “term” is often used for keyword fields.
4. How can I monitor the health of my Elasticsearch cluster?
You can check the health of your Elasticsearch cluster using the following HTTP request:GET /_cat/health?v
This command provides information about the overall health, including the status, number of nodes, and more.
5. What is the purpose of Elasticsearch aggregations?
Aggregations in Elasticsearch help analyze and summarize data, providing insights into the distribution and relationships within your dataset. They can be used to perform calculations, grouping, and statistical operations on your indexed data.