## Summary Remove vestigial field mappings from `ee/lib/elastic/latest/config.rb` and reindex the combined Advanced Search index. The combined index now only stores **Milestone, Snippet, and Blob** documents; many of its current mappings are leftovers from doc types that moved to dedicated indices. **Scope: main index only.** This issue removes leftover field mappings from the main combined Advanced Search index (`gitlab-production`, defined in `ee/lib/elastic/latest/config.rb`) and reindexes only that index (`targets: ['Repository']`). The separate indices (work items, merge requests, notes, projects, commits, wikis, users, and others) keep their own mappings and fields. They are not changed and do not need a reindex. The "From Issues / From Merge Requests / ..." groupings below show where each field came from, not which index loses it. Part of &22059. ## Vestigial fields to remove Each group is from a doc type that has moved to its own index. Live writes/queries have already been audited (see epic &22059). **From Issues (now in Work Item separate index)** - `confidential`, `assignee_id` - nested `issue` block (`issue.assignee_id`, `issue.author_id`, `issue.confidential`) **From Merge Requests (`merge_request_config.rb`)** - `target_branch`, `source_branch`, `merge_status` - `source_project_id`, `target_project_id` **From Notes (`note_config.rb`)** - `note` (text), `noteable_type`, `noteable_id` **From Projects (`project_config.rb`)** - `name`, `path`, `name_with_namespace`, `path_with_namespace` - `last_activity_at`, `last_pushed_at` - `ci_catalog`, `readme_content` **From Snippets-as-project-feature & Wikis (not used in this index)** - `snippets_access_level`, `wiki_access_level` **From Commits (`commit_config.rb`)** - nested `commit` block **`join_field` relations** - Remove `join_field` entirely in this same reindex, instead of trimming its relations. Nothing reads it: no `has_parent`/`has_child` query reaches the combined index (see #630682). - Both writers must stop sending it, and stored documents must be stripped, before the mapping drop. That work is tracked in #630682, which blocks this issue. ## Fields to keep `id`, `iid`, `type`, `schema_version`, `title`, `description`, `state`, `created_at`, `updated_at`, `project_id`, `author_id`, `visibility_level`, `archived`, `traversal_ids`, `namespace_id` (group milestone, !257456), `issues_access_level` (milestone), `merge_requests_access_level` (milestone), `repository_access_level` (blob), nested `blob` block. `namespace_id` is kept because !257456 (group milestones in Advanced Search) writes it on group milestone documents in the combined index. Dropping it under the `dynamic: 'strict'` mapping would reject those documents. ## Tasks - [x] Re-confirm each vestigial field has zero live references in indexer and query code targeting the combined index - Details in the 2026-10-01 comment. - [ ] Confirm that no stored document in the combined index still has any of the removed fields (an `exists` count per field), and strip any that remain with a `MigrationRemoveFieldsHelper` migration before the reindex - The mapping is `dynamic: 'strict'` and the reindex copies `_source` as-is, so one such document fails its slice and the reindex aborts on the document count check - [x] Dry run on a local GDK index: only `join_field` is present (on every blob and milestone document); every other removed field has a count of 0. - [x] Checked locally (Elasticsearch 9.4.4) that `update_by_query` with `ctx._source.remove('join_field')` works while the join mapping still exists, and routing is kept. A document that still has `join_field` fails the reindex into the strict mapping. - [ ] Run the `exists` counts on staging and production (snippet in the 2026-10-01 comment). - [ ] Update `ee/lib/elastic/latest/config.rb` to drop the fields listed above and `join_field` - [ ] Add an Advanced Search migration that reindexes the combined index into a fresh index with the trimmed mapping, swaps the alias, deletes the old physical index - [ ] Use the new per-data-type pause (#381705) to pause **Milestone, Snippet, and Blob** writes during the swap - [ ] Update specs / mapping fixtures (incl. `ee/spec/lib/ee/gitlab/elastic/helper_spec.rb`) - [ ] #630682 is done: `join_field` is no longer written by Rails or `gitlab-elasticsearch-indexer`, and is stripped from stored documents - [ ] Verify on staging: Milestone, Snippet, and Blob search remain functional end-to-end ## Blocked by - #381705 — Zero downtime reindexing should pause only the indexes specified - #381705 was closed as stale on 2026-09-05 without being implemented. `ClusterReindexingService` still pauses all indexing for a single-index reindex. This needs to be reopened, or this issue needs to accept a global pause. - #630682 — Remove the unused join_field from the main Advanced Search index ## Note on sequencing This reindex changes the combined index's mapping. If &20721's ID type migration is also blocked on #381705, both changes should ideally be folded into a single reindex pass to avoid reindexing the same data twice. Coordinate with the owner of &20721 before starting.