# 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>
# Which Problems Are Solved
Adds the possibility to mirror an existing database to a new one.
For that a new command was added `zitadel mirror`. Including it's
subcommands for a more fine grained mirror of the data.
Sub commands:
* `zitadel mirror eventstore`: copies only events and their unique
constraints
* `zitadel mirror system`: mirrors the data of the `system`-schema
* `zitadel mirror projections`: runs all projections
* `zitadel mirror auth`: copies auth requests
* `zitadel mirror verify`: counts the amount of rows in the source and
destination database and prints the diff.
The command requires one of the following flags:
* `--system`: copies all instances of the system
* `--instance <instance-id>`, `--instance <comma separated list of
instance ids>`: copies only the defined instances
The command is save to execute multiple times by adding the
`--replace`-flag. This replaces currently existing data except of the
`events`-table
# Additional Changes
A `--for-mirror`-flag was added to `zitadel setup` to prepare the new
database. The flag skips the creation of the first instances and initial
run of projections.
It is now possible to skip the creation of the first instance during
setup by setting `FirstInstance.Skip` to true in the steps
configuration.
# Additional info
It is currently not possible to merge multiple databases. See
https://github.com/zitadel/zitadel/issues/7964 for more details.
It is currently not possible to use files. See
https://github.com/zitadel/zitadel/issues/7966 for more information.
closes https://github.com/zitadel/zitadel/issues/7586
closes https://github.com/zitadel/zitadel/issues/7486
### Definition of Ready
- [x] I am happy with the code
- [x] Short description of the feature/issue is added in the pr
description
- [x] PR is linked to the corresponding user story
- [x] Acceptance criteria are met
- [x] All open todos and follow ups are defined in a new ticket and
justified
- [x] Deviations from the acceptance criteria and design are agreed with
the PO and documented.
- [x] No debug or dead code
- [x] My code has no repetitions
- [x] Critical parts are tested automatically
- [ ] Where possible E2E tests are implemented
- [x] Documentation/examples are up-to-date
- [x] All non-functional requirements are met
- [x] Functionality of the acceptance criteria is checked manually on
the dev system.
---------
Co-authored-by: Livio Spring <livio.a@gmail.com>
* fix(db): add additional connection pool for projection spooling
* use correct connection pool for projections
---------
Co-authored-by: Livio Spring <livio.a@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.
