On 14 January 2021, Elastic N.V. announced that they would be dual licensing ElasticSearch under SSPL and the Elastic License starting with version 7.11.0 which was released on 10 February 2021. The last release of ElasticSearch under the Apache License 2.0 was 7.10.2 on 14 January 2021.
https://en.wikipedia.org/wiki/Elastic_NV https://www.elastic.co/blog/licensing-change https://en.wikipedia.org/wiki/Server_Side_Public_License https://www.elastic.co/licensing/elastic-license https://github.com/elastic/elasticsearch/releases/tag/v7.11.0 https://github.com/elastic/elasticsearch/releases/tag/v7.10.2 Neither the SSPL nor the Elastic License are OSI or FSF approved. They are proprietary licenses, and the board of OSI directors describe the SSPL as a "fauxpen" license. Foal currently uses elasticsearch[async] version >=7.13.1,<7.14.0, which are marked, correctly, as being released under the Apache License 2.0 because the _Python libraries_ are licensed as such, but the software with which they communicate upstream, the ElasticSearch database, is proprietary. https://opensource.org/sspl-not-open-source https://github.com/apache/incubator-ponymail-foal/blob/aec347deb09154959d278a4a918f3779699434a6/tools/requirements.txt The ASF does allow its projects to interact with external data sources served by software which does not use an approved license: "It does not matter, unless the terms for that platform affect the Apache product's licensing. For example, creating a product that runs on Windows or Java, uses a web service such as Google Services or Yahoo Search, or is a plugin for a product such as JBoss or JIRA is fine" https://www.apache.org/legal/resolved.html#category-x But Foal will eventually have to take a permanent stance on this issue because of the ElasticSearch compatibility matrix. The ElasticSearch 7.10 series, the last to be licensed under the Apache License 2.0, is already not available for installation on Debian 11. It requires OpenJDK 11, which has a limited support lifespan and is currently slated to end in "October 2024". This means that Foal has to decide what to do about ElasticSearch within two years at most. https://www.elastic.co/support/matrix https://access.redhat.com/articles/1299013 It would be possible to migrate to OpenSearch, a fork still using the Apache License 2.0. But it is not possible to maintain compatibility with both ElasticSearch and OpenSearch because the Python clients were made incompatible on the ElasticSearch side on 30 June 2021, and although OpenSearch declared that they will try to maintain client compatibility, there is no such compatibility noted in their own matrix. There is also no approved migratation method from ElasticSearch on the server side from 8.0 onwards to OpenSearch, from either team. https://github.com/elastic/elasticsearch-py/pull/1623 https://aws.amazon.com/blogs/opensource/keeping-clients-of-opensearch-and-elasticsearch-compatible-with-open-source/ https://github.com/opensearch-project/opensearch-py/blob/main/COMPATIBILITY.md --sbp
