Elasticsearch, developed by Elastic, is a free and open-source RESTful search to use the trends to analyze and predict the structured and unstructured data. After being released in 2010, it has exponentially grown to become a leading search engine and is used for Business analytics, security intelligence and log analytics. It is highly scalable and allows storing, using and retrieving data and analyzing real-time.

Why Elasticsearch?

• The search is very fast and the installation process and integration are very easy.
• Features: Excellent flexibility to absorb multiple types of data sources, and great integration with applications like Logstash and Kibana. 
• Elasticsearch has turned into a solution that you’d typically integrate into another to a fully customizable standalone solution. It has everything in one spot now, with hardly a need to use 3rd party plugins/extensions.
• Impressive speed of search of indexed documents. Millions of documents can be processed and be ready for search immediately.
• Scalability: One can start with 1 node but when the project grows, simply adding nodes to the cluster and elastic search manages everything by itself and transfer data equally among nodes.
• Data aggregation: When the developer can set a query inside query and then split response for buckets and aggregations do not add any time for query execution.