Elasticsearch is a distributed, RESTful search and analytics engine that allows for fast searching, filtering, and analysis of large volumes of data. It is document-based and stores structured and unstructured data in JSON documents within configurable indices. Documents can be queried using a simple query string syntax or more complex queries using the domain-specific query language. Elasticsearch also supports analytics through aggregations that can perform metrics and bucketing operations on document fields.

1. Introduction to
Elasticsearch
Jason Austin - @jason_austin

2. The Problem
• You are building a website to find beers
• You have a huge database of beers and
breweries to sift through
• You want simple keyword-based searching
• You also want structured searching, like finding
all beers > 7% ABV
• You want to run some analytics on what beers
are in your dataset

3. Enter Elasticsearch
• Lucene based
• Distributed
• Fast
• RESTful interface
• Document-Based with JSON

5. Install Elasticsearch
• Download from http://elasticsearch.org
• Requires Java to run

6. Run Elasticsearch
• From the install directory:
./bin/elasticsearch -d!
!
http://localhost:9200/!

7. Communicating
• Elasticsearch listens to RESTful HTTP
requests
• GET, POST, PUT, DELETE
• CURL works just fine

8. ES Structure
Relational DB
Databases
Tables
Rows
Columns
Elasticsearch
Indices
Types
Documents
Fields

9. ES Structure
Elasticsearch
Indices
Types
Documents
Fields
Elasticsearch
phpbeer
beer
Pliny the Elder
ABV, Name, Desc

10. Create an Index
curl -XPOST 'http://localhost:9200/phpbeer'

11. What to Search?
• Define the types of things to search
• Beer
• Brewery - Maybe later

12. Define a Beer
• Name
• Style
• ABV
• Brewery
‣ Name
‣ City

13. Beer JSON
{
! "name": "Pliny the Elder",
! "style": "Imperial India Pale Ale",
! "abv": 7.0,
! "brewery": {
! ! "name": "Russian River Brewing Co.",
! ! "city": "Santa Rosa",
"state": "California"
! }
}

14. SavingThe Beer
curl -XPOST 'http://localhost:9200/
phpbeer/beer/1' -d '{
! "name": "Pliny the Elder",
! "style": "Imperial India Pale Ale",
! "abv": 7.0,
! "brewery": {
! ! "name": "Russian River Brewing Co.",
! ! "city": "Santa Rosa",
"state": "California"
! }
}'

15. Getting a beer
curl -XGET 'http://localhost:9200/phpbeer/
beer/1?pretty'

16. Updating a Beer
curl -XPOST 'http://localhost:9200/
phpbeer/beer/1' -d '{
! "name": "Pliny the Elder",
! "style": "Imperial India Pale Ale",
! "abv": 8.0,
! "brewery": {
! ! "name": "Russian River Brewing Co.",
! ! "city": "Santa Rosa",
"state": "California"
! }
}'

17. POSTvs PUT
• POST
• No ID - Creates new doc, assigns ID
• With ID - Updates or creates new doc
• PUT
• No ID - Error
• With ID - Updates doc

18. Delete a Beer
curl -XDELETE 'http://localhost:9200/
phpbeer/beer/1'

19. Finally! Searching!
curl -XGET 'http://localhost:9200/_search?
pretty&q=pliny'

20. Specific Field Searching
curl -XGET 'http://localhost:9200/_search?
pretty&q=style:pliny'!
curl -XGET 'http://localhost:9200/_search?
pretty&q=style:imperial'

21. Alternate Approach
• Search using DSL (Domain Specific
Language)
• JSON in request body

22. DSL Searching
curl -XGET 'http://localhost:9200/_search?
pretty' -d '{
"query" : {
"match" : {
"style" : "imperial"
}
}
}'

23. DSL = Query + Filter
• Query - “How well does the document
match”
• Filter - Yes or No question on the field

24. Query DSL
• match
• Used to query across all fields for a string
• match_phrase
• Used to query an exact phrase
• match_all
• Matches all documents
• multi_match
• Runs the same match query on multiple fields

25. Filter DSL
• term
• Exact match on a field
• range
• Match numbers over a specified range
• exists / missing
• Match based on the existence of a value
for a field

26. More Complex Search
• Find beer whose styles include “Pale
Ale” that are less than 7% ABV

27. Match + Range
curl -XGET 'http://localhost:9200/_search?pretty'
-d '{
"query" : {
"match" : {
"style" : "pale ale"
}
},
"filter" : {
"range" : {
"abv" : { "lt" : 7 }
}
}
}'

28. Embedded Field Search
curl -XGET 'http://localhost:9200/_search?pretty'
-d '{
"query" : {
"match" : {
"brewery.state" : "California"
}
}
}'

29. Highlighting Search Results

30. Highlighting Search Results
curl -XGET 'http://localhost:9200/_search?pretty'
-d '{
"query" : {
"match" : {
"style" : "pale ale"
}
},
"highlight": {
"fields" : {
"style" : {}
}
}
}'

31. Aggregations
• Collect analytics on your documents
• 2 main types
• Bucketing
• Produce a set of buckets with documents
in them
• Metric
• Compute metrics over a set of documents

32. Bucketing Aggregations

33. Metric Aggregations
• How many beers exist of each style?
• What is the average ABV of beers for
each style?
• How many beers exist that are brewed
in California?

34. What is the average ABV of beers for each style?
curl -XGET 'http://localhost:9200/_search?pretty' -d '{
"aggs" : {
"all_beers" : {
"terms" : { "field" : "style" },
"aggs" : {
"avg_abv" : {
"avg" : { "field" : "abv" }
}
}
}
}
}'

35. Mappings
• Define how ES searches
• Completely optional
• Must re-index after defining mapping

36. Create Index with Mapping
curl -XPOST localhost:9200/phpbeer -d '{
"mappings" : {
"beer" : {
"_source" : { "enabled" : true },
"properties" : {
"style" : {
"type" : "string",
"index" : "not_analyzed"
}
}
}
}
}'
curl -XDELETE localhost:9200/phpbeer

37. What is the average ABV of beers for each style?
curl -XGET 'http://localhost:9200/_search?pretty' -d '{
"aggs" : {
"all_beers" : {
"terms" : { "field" : "style" },
"aggs" : {
"avg_abv" : {
"avg" : { "field" : "abv" }
}
}
}
}
}'

38. Non-Analyzed Fields
curl -XGET 'http://localhost:9200/_search?
pretty&q=style:imperial'!
curl -XGET 'http://localhost:9200/_search?
pretty&q=style:hefeweizen'

39. Flexibility
• Mixing aggregations, filters and queries
all together
• What beers have the word “night” in
the name that are between 4 and 6 %
ABV, broken down by style.

40. Elasticsearch and PHP
• Elasticsearch PHP Lib
https://github.com/elasticsearch/elasticsearch-php
• Elastica
http://elastica.io/

41. Other Awesome ES Features
• Search analyzers
• Geo-based searching
• Elasticsearch Plugins
• kopf - http://localhost:9200/_plugin/kopf

42. Questions?
• @jason_austin
• http://www.pintlabs.com
• https://joind.in/10821