# Which Problems Are Solved
Add a cache implementation using Redis single mode. This does not add
support for Redis Cluster or sentinel.
# How the Problems Are Solved
Added the `internal/cache/redis` package. All operations occur
atomically, including setting of secondary indexes, using LUA scripts
where needed.
The [`miniredis`](https://github.com/alicebob/miniredis) package is used
to run unit tests.
# Additional Changes
- Move connector code to `internal/cache/connector/...` and remove
duplicate code from `query` and `command` packages.
- Fix a missed invalidation on the restrictions projection
# Additional Context
Closes#8130
# Which Problems Are Solved
Milestones used existing events from a number of aggregates. OIDC
session is one of them. We noticed in load-tests that the reduction of
the oidc_session.added event into the milestone projection is a costly
business with payload based conditionals. A milestone is reached once,
but even then we remain subscribed to the OIDC events. This requires the
projections.current_states to be updated continuously.
# How the Problems Are Solved
The milestone creation is refactored to use dedicated events instead.
The command side decides when a milestone is reached and creates the
reached event once for each milestone when required.
# Additional Changes
In order to prevent reached milestones being created twice, a migration
script is provided. When the old `projections.milestones` table exist,
the state is read from there and `v2` milestone aggregate events are
created, with the original reached and pushed dates.
# Additional Context
- Closes https://github.com/zitadel/zitadel/issues/8800
