[blackheaven]

https://wearezeta.atlassian.net/browse/WPB-22956

Checklist

• Add a new entry in an appropriate subdirectory of changelog.d
• Read and follow the PR guidelines

[blackheaven]

Heads-up: the integration test added here (Test/Migration/Team.hs) reuses admin (the owner of tid1) for the tid2-tid4 assertions, but every createTeam mints a fresh owner and team-member listing requires membership — those assertions would 404. Fixed on the stacked branch in #5635 (this PR should be merged together with or after #5635, or the fix cherry-picked).

[Copilot]

🟡 Changes recommended

Critical write-ordering and deletion-state bugs can overwrite acknowledged updates, leave Cassandra and PostgreSQL inconsistent, and make interrupted deletions unrecoverable or allow deleted teams to be restored.

5 open issues

• Concurrent writes can leave Cassandra and PostgreSQL out of sync · New
• Backfill can overwrite newer dual-written team metadata · New
• PostgreSQL deletion can strand incomplete Cassandra cleanup · New
• Later PostgreSQL writes can undo terminal team deletion · New
• Missing timestamps are converted to fabricated 1858 dates · New

What changed in this PR

This PR adds staged migration of team metadata from Cassandra to PostgreSQL, while keeping team membership data in Cassandra.

Changes:

• Adds PostgreSQL storage, dual-write support, and a background migration with metrics.
• Wires storage selection and migration controls into services, Helm configuration, and documentation.
• Adds serialization tests and integration coverage for migration and cutover.

File	Description
services/​galley/​src/​Galley/​App.hs	Selects the configured team-store interpreter.
services/​galley/​galley.integration.yaml	Enables PostgreSQL team metadata in integration tests.
services/​brig/​brig.integration.yaml	Adds the team storage setting.
services/​background-worker/​test/​Test/​Wire/​Util.hs	Updates test configuration with team storage.
services/​background-worker/​test/​Test/​Wire/​BackendNotificationPusherSpec.hs	Updates migration-option fixtures.
services/​background-worker/​src/​Wire/​PostgresMigrations.hs	Starts team migration and registers metrics.
services/​background-worker/​src/​Wire/​Effects.hs	Selects the worker's team-store interpreter.
services/​background-worker/​src/​Wire/​BackgroundWorker/​Options.hs	Adds the team migration flag.
services/​background-worker/​src/​Wire/​BackgroundWorker.hs	Manages team migration startup and cleanup.
services/​background-worker/​background-worker.integration.yaml	Configures team storage and migration defaults.
postgres-schema.sql	Records the new team table and primary key.
libs/​wire-subsystems/​wire-subsystems.cabal	Exposes the new team-store modules.
libs/​wire-subsystems/​src/​Wire/​TeamStore/​Postgres.hs	Implements PostgreSQL team metadata operations.
libs/​wire-subsystems/​src/​Wire/​TeamStore/​Migration.hs	Copies Cassandra team metadata into PostgreSQL.
libs/​wire-subsystems/​src/​Wire/​TeamStore/​DualWrite.hs	Mirrors metadata writes during migration.
libs/​wire-subsystems/​src/​Wire/​TeamStore/​Cassandra/​Queries.hs	Adds the migration scan query.
libs/​wire-subsystems/​src/​Wire/​PostgresMigrationOpts.hs	Adds team storage selection.
libs/​wire-subsystems/​postgres-migrations/​20261022080836-create-team.sql	Creates the PostgreSQL team metadata table.
libs/​wire-api/​test/​unit/​Test/​Wire/​API/​Roundtrip/​PostgresMarshall.hs	Tests team-type serialization round trips.
libs/​wire-api/​src/​Wire/​API/​Team/​SearchVisibility.hs	Adds PostgreSQL search-visibility encoding.
libs/​wire-api/​src/​Wire/​API/​Team.hs	Adds PostgreSQL binding and icon encoding.
libs/​wire-api/​src/​Wire/​API/​Routes/​Internal/​Galley/​TeamsIntra.hs	Adds PostgreSQL team-status encoding.
integration/​test/​Test/​Migration/​Team.hs	Tests staged migration and PostgreSQL cutover.
integration/​integration.cabal	Registers the migration test module.
hack/​helm_vars/​wire-server/​values.yaml.gotmpl	Passes team storage selection into Galley.
hack/​helm_vars/​common.yaml.gotmpl	Defines the preferred team storage value.
docs/​src/​developer/​reference/​config-options.md	Documents team migration settings and metrics.
charts/​wire-server/​values.yaml	Adds default storage and migration settings.
charts/​wire-server/​templates/​background-worker/​configmap.yaml	Renders the team migration flag.
changelog.d/​5-internal/​WPB-22956	Records the team metadata migration.

_{Review effort: Balanced}