Apache 2.0→SSPL. AWS forked. Elastic added AGPL as another license option in 2024, but did not fully reverse the SSPL/ELv2 change. Now under Linux Foundation.
Elasticsearch is a distributed search and analytics engine built on Apache Lucene, widely used for log analytics, full-text search, and observability. It powers search functionality for thousands of companies and is a core component of the ELK (Elasticsearch, Logstash, Kibana) stack. OpenSearch forked from Elasticsearch 7.10.2 and has since diverged significantly, adding features like built-in security, anomaly detection, and SQL support.
The Elasticsearch saga is one of open source's most dramatic licensing wars, and it starts with a grudge. AWS launched its managed Elasticsearch service in 2015, with CTO Werner Vogels publicly declaring it a 'great partnership with Elastic.' There was one problem: Elastic CEO Shay Banon says there was no partnership, and no collaboration. AWS had simply taken the Apache 2.0-licensed code and built a service around it, using the Elasticsearch name. Elastic tried to fight on trademark grounds but found themselves outgunned — Banon later described having '1,000 lawyers thrown at us.'
In January 2021, Elastic pulled the trigger: they relicensed Elasticsearch and Kibana from Apache 2.0 to a dual-license under the Server Side Public License (SSPL) and the Elastic License. The SSPL — originally devised by MongoDB — effectively prevents cloud providers from offering the software as a managed service without open-sourcing their entire stack. It was a direct shot at AWS.
AWS responded exactly as you'd expect a company with unlimited engineering resources would: they forked the last Apache 2.0 version (Elasticsearch 7.10.2) and created OpenSearch. The fork launched in April 2021 and reached version 1.0 by July. It wasn't a scrappy community effort — it was a corporate fork backed by the world's largest cloud provider, complete with dedicated engineering teams and enterprise support.
The twist came in 2024. Elastic added AGPL as a third licensing option, technically making Elasticsearch 'open source' again. Meanwhile, AWS transferred OpenSearch governance to the Linux Foundation, establishing the OpenSearch Software Foundation. The irony is thick: Elastic's aggressive licensing move intended to hurt AWS instead created a well-funded competitor that now has independent governance. Many developers who felt burned by the original license switch have said they won't go back.
AWS launches managed Elasticsearch service, Elastic protests trademark misuse
AWS launches Open Distro for Elasticsearch as an Apache 2.0 distribution
Elastic relicenses Elasticsearch and Kibana from Apache 2.0 to SSPL/Elastic License
AWS announces it will fork Elasticsearch
OpenSearch project publicly launched
OpenSearch 1.0 released
Elastic adds AGPL license option, declares Elasticsearch 'open source again'
AWS transfers OpenSearch governance to Linux Foundation
“The problem was never AWS taking Elasticsearch and providing it, it was calling it AWS Elasticsearch and implying that it's their service.”
“Great partnership between elastic and AWS”
OpenSearch fundamentally changed the calculus around open source licensing in the cloud era. It proved that when a company changes licenses to protect against cloud providers, the cloud providers can simply fork and out-resource you. The existence of a well-funded, Linux Foundation-governed alternative forced Elastic to reverse course and return to an OSI-approved license — a remarkable humiliation for a company that had staked its strategy on license restrictions.
The broader ecosystem impact was seismic. OpenSearch validated the 'fork and fund' playbook that would later be repeated with Valkey (Redis fork) and OpenTofu (Terraform fork). It also demonstrated that trust, once broken with the open source community, is extremely difficult to rebuild — many developers who migrated to OpenSearch have shown no interest in returning to Elasticsearch even after the AGPL re-licensing.