Book Image

Elasticsearch Indexing

By : Huseyin Akdogan
Book Image

Elasticsearch Indexing

By: Huseyin Akdogan

Overview of this book

Beginning with an overview of the way ElasticSearch stores data, you’ll begin to extend your knowledge to tackle indexing and mapping, and learn how to configure ElasticSearch to meet your users’ needs. You’ll then find out how to use analysis and analyzers for greater intelligence in how you organize and pull up search results – to guarantee that every search query is met with the relevant results! You’ll explore the anatomy of an ElasticSearch cluster, and learn how to set up configurations that give you optimum availability as well as scalability. Once you’ve learned how these elements work, you’ll find real-world solutions to help you improve indexing performance, as well as tips and guidance on safety so you can back up and restore data. Once you’ve learned each component outlined throughout, you will be confident that you can help to deliver an improved search experience – exactly what modern users demand and expect.
Table of Contents (15 chapters)
Elasticsearch Indexing
About the Author
About the Reviewer

Explaining the architecture of distribution

Initially, we don't have an index and data when we start a single node. In this case, it means we have an empty cluster. When we create an index with the default settings, the cluster will take the following view:

As mentioned earlier, Elasticsearch creates five primary shards and a copy of each primary shard by default. But replicas do not appear in the preceding view. Why?

Let's look for the answer to our question by using the Cat API:

curl -XGET 'localhost:9200/_cat/shards'

my_index 4 p STARTED    0144b Digitek
my_index 4 r UNASSIGNED
my_index 0 p STARTED    0144b Digitek
my_index 0 r UNASSIGNED
my_index 3 p STARTED    0144b Digitek
my_index 3 r UNASSIGNED
my_index 1 p STARTED    0144b Digitek
my_index 1 r UNASSIGNED
my_index 2 p STARTED    0144b Digitek
my_index 2 r UNASSIGNED

As you can see, there are five shards in our cluster, their states are STARTED, and there are other five...