ELKOpenSearch

ELKOpenSearch refers to a stack of open-source software used for searching, viewing, and analyzing large volumes of data in real-time. The name is a portmanteau, combining "ELK" which historically stood for Elasticsearch, Logstash, and Kibana, with "OpenSearch," a fork of Elasticsearch and Kibana.

Elasticsearch is a distributed, RESTful search and analytics engine capable of addressing a growing number of use cases. Logstash is a server-side data processing pipeline that ingests data from a multitude of sources simultaneously, transforms it, and then sends it to a "stash" like Elasticsearch. Kibana is a data visualization and exploration tool that can visualize Elasticsearch data and other data sources.

The shift to OpenSearch occurred when Elastic NV, the company behind Elasticsearch and Kibana, relicensed their software under the Server Side Public License (SSPL). This license was not considered truly open-source by some in the community, leading to the creation of the OpenSearch project, a community-driven, Apache 2.0 licensed fork. Therefore, ELKOpenSearch often refers to deployments using OpenSearch instead of Elasticsearch, along with compatible visualization and data ingestion tools. These stacks are commonly used for log analysis, application performance monitoring, security analytics, and business intelligence.