Book Image

Elasticsearch Essentials

Book Image

Elasticsearch Essentials

Overview of this book

With constantly evolving and growing datasets, organizations have the need to find actionable insights for their business. ElasticSearch, which is the world's most advanced search and analytics engine, brings the ability to make massive amounts of data usable in a matter of milliseconds. It not only gives you the power to build blazing fast search solutions over a massive amount of data, but can also serve as a NoSQL data store. This guide will take you on a tour to become a competent developer quickly with a solid knowledge level and understanding of the ElasticSearch core concepts. Starting from the beginning, this book will cover these core concepts, setting up ElasticSearch and various plugins, working with analyzers, and creating mappings. This book provides complete coverage of working with ElasticSearch using Python and performing CRUD operations and aggregation-based analytics, handling document relationships in the NoSQL world, working with geospatial data, and taking data backups. Finally, we’ll show you how to set up and scale ElasticSearch clusters in production environments as well as providing some best practices.
Table of Contents (18 chapters)
Elasticsearch Essentials
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Index

Introducing the aggregation framework


The aggregation functionality is completely different from search and enables you to ask sophisticated questions of the data. The use cases of aggregation vary from building analytical reports to getting real-time analysis of data and taking quick actions.

Also, despite being different in functionality, aggregations can operate along the usual search requests. Therefore, you can search or filter your data, and at the same time, you can also perform aggregation on the same datasets matched by search/filter criteria in a single request. A simple example can be to find the maximum number of hashtags used by users related to tweets that has crime in the text field. Aggregations enable you to calculate and summarize data about the current query on the fly. They can be used for all sorts of tasks such as dynamic counting of result values to building a histogram.

Aggregations come in two flavors: metrics and buckets.

  • Metrics: Metrics are used to do statistics...