Book Image

Learning Elasticsearch

By : Abhishek Andhavarapu
Book Image

Learning Elasticsearch

By: Abhishek Andhavarapu

Overview of this book

Elasticsearch is a modern, fast, distributed, scalable, fault tolerant, and open source search and analytics engine. You can use Elasticsearch for small or large applications with billions of documents. It is built to scale horizontally and can handle both structured and unstructured data. Packed with easy-to- follow examples, this book will ensure you will have a firm understanding of the basics of Elasticsearch and know how to utilize its capabilities efficiently. You will install and set up Elasticsearch and Kibana, and handle documents using the Distributed Document Store. You will see how to query, search, and index your data, and perform aggregation-based analytics with ease. You will see how to use Kibana to explore and visualize your data. Further on, you will learn to handle document relationships, work with geospatial data, and much more, with this easy-to-follow guide. Finally, you will see how you can set up and scale your Elasticsearch clusters in production environments.
Table of Contents (11 chapters)
10
Exploring Elastic Stack (Elastic Cloud, Security, Graph, and Alerting)

Handling relations between different document types

In the relational world, data is often divided into multiple tables and is linked using foreign keys. To get the data, a join is used to combine data from one or more tables. But in the NoSQL world, data is usually denormalized and stored as one big document. However, it is often advantageous to store these documents separately. Data in Elasticsearch is immutable. An update to an existing document means fetching the old document, applying the change, and re-indexing it as a new document. The update is an expensive operation. If possible, we have to keep the updates to a minimum.

For example, a blog article can have one or more comments, and an order can have one or more line items. If we can separate the article and comment documents, we don't have to update the article when there is a new comment. Elasticsearch provides...