### Overview GitLab's Advanced Search must offer compatibility with OpenSearch due to the high volume of customers that use AWS managed services. This will also start compatibility needed for Gitlab Dedicated. Opensearch is a fast-growing Opensource version of elasticsearch available through AWS Managed services. AWS Managed services are very popular with Gitlab self-managed customers. ### Compatibility Offering the Compatibility of GitLab Opensearch is required to ensure that self-managed customers can maintain the critical patches that fix vulnerabilities and take advantage of the common performance enhancements in the new versions. #### Opensearch - Opensearch is a fork from Elasticsearch 7.10.2. W - Opensearch created a new Client that was not compatible with Gitlab [Draft: Update ES client to 7.13.3, deprecate _type](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/79949) ### Deprecation To offer compatibility for Elasticsearch across multiple versions of GitLab, we have to continually deprecate older versions of Elasticsearch. Deprecations should happen outside of the Major milestone used for most deprecations as Elsticsearch depreciation maintains its schedule. - [Deprecate Elasticsearch 6.8.x in GitLab 15.0](https://gitlab.com/gitlab-org/gitlab/-/issues/350275)) - Remove Migrations TBD- https://gitlab.com/gitlab-org/gitlab/-/issues/323310 - Rails https://gitlab.com/gitlab-org/gitlab/-/merge_requests/79949 - Indexer https://gitlab.com/gitlab-org/gitlab-elasticsearch-indexer/-/merge_requests/147 ### Testing/QA - [Run Opensearch with our current test framework](https://gitlab.com/gitlab-org/gitlab/-/issues/348476) ### Customer Demand Customers reference the need for Opensearch compatibility. - gitlab#327560 (comment 820229157) - gitlab#327560 (comment 818424990) - gitlab#327560 (comment 813452811) - gitlab#327560 (comment 790862308) - https://gitlab.zendesk.com/agent/tickets/261224 - https://gitlab.zendesk.com/agent/tickets/262214 - gitlab#327560 (comment 712478359) ### What are the midterm and final "exams" to check for success? - [x] [Run Opensearch with our current test framework](https://gitlab.com/gitlab-org/gitlab/-/issues/348476) - [ ] Make Tests work with Opensearch - [ ] Fix Issues found for compatibility - [ ] [Opensearch compatibility: Blob search fails in GDK](https://gitlab.com/gitlab-org/gitlab/-/issues/356471) - [ ] [Opensearch Compatibility: Mapping parser errors](https://gitlab.com/gitlab-org/gitlab/-/issues/356626) - [ ] Close [Support OpenSearch as Advanced Search backend](https://gitlab.com/gitlab-org/gitlab/-/issues/327560) ### Release Notes Advanced Search was not compatible with OpenSearch, and GitLab customers using AWS managed services have had to use the older versions of Elasticsearch with Advanced Search. Starting with GitLab 15.0, Advanced Search is compatible with OpenSearch. Opensearch compatibility is the most frequent request we have had from customers. We have added upgrade instructions and a setup guide for OpenSearch in the [Advanced Search section](https://docs.gitlab.com/ee/user/search/advanced_search.html) of the GitLab documentation.