# Which Problems Are Solved
If many events are written to the same aggregate id it can happen that
zitadel [starts to retry the push
transaction](48ffc902cc/internal/eventstore/eventstore.go (L101))
because [the locking
behaviour](48ffc902cc/internal/eventstore/v3/sequence.go (L25))
during push does compute the wrong sequence because newly committed
events are not visible to the transaction. These events impact the
current sequence.
In cases with high command traffic on a single aggregate id this can
have severe impact on general performance of zitadel. Because many
connections of the `eventstore pusher` database pool are blocked by each
other.
# How the Problems Are Solved
To improve the performance this locking mechanism was removed and the
business logic of push is moved to sql functions which reduce network
traffic and can be analyzed by the database before the actual push. For
clients of the eventstore framework nothing changed.
# Additional Changes
- after a connection is established prefetches the newly added database
types
- `eventstore.BaseEvent` now returns the correct revision of the event
# Additional Context
- part of https://github.com/zitadel/zitadel/issues/8931
---------
Co-authored-by: Tim Möhlmann <tim+github@zitadel.com>
Co-authored-by: Livio Spring <livio.a@gmail.com>
Co-authored-by: Max Peintner <max@caos.ch>
Co-authored-by: Elio Bischof <elio@zitadel.com>
Co-authored-by: Stefan Benz <46600784+stebenz@users.noreply.github.com>
Co-authored-by: Miguel Cabrerizo <30386061+doncicuto@users.noreply.github.com>
Co-authored-by: Joakim Lodén <Loddan@users.noreply.github.com>
Co-authored-by: Yxnt <Yxnt@users.noreply.github.com>
Co-authored-by: Stefan Benz <stefan@caos.ch>
Co-authored-by: Harsha Reddy <harsha.reddy@klaviyo.com>
Co-authored-by: Zach H <zhirschtritt@gmail.com>
This implementation increases parallel write capabilities of the eventstore.
Please have a look at the technical advisories: [05](https://zitadel.com/docs/support/advisory/a10005) and [06](https://zitadel.com/docs/support/advisory/a10006).
The implementation of eventstore.push is rewritten and stored events are migrated to a new table `eventstore.events2`.
If you are using cockroach: make sure that the database user of ZITADEL has `VIEWACTIVITY` grant. This is used to query events.
