Technical Advisory 10004

Date and Version

Version: 2.39.0

Date: 2023-10-14

Description

Due to storage optimisations ZITADEL changes the behavior of sequences. This change improves command (create, update, delete) performance of ZITADEL.

Sequences are no longer unique inside an instance. From now on sequences are upcounting per aggregate id. For example sequences of newly created users begin at 1. Existing sequences remain untouched.

Statement

This change is tracked in the following PR: new eventstore framework. As soon as the release version is published, we will include the version here.

Mitigation

If you use the ListEvents API to scrape events use the creation date instead of the sequence. If you use sequences on a list of objects it's no longer garanteed to have unique sequences across the list. Therefore it's recommended to use the change data of the objects instead.

Impact

Once this update has been released and deployed, sequences are no longer unique inside an instance. ZITADEL will increase parallel write capabilities, because there is no global sequence to track anymore. Editor service does not respond the different services of ZITADEL anymore, it returns zitadel. As we are switching to resource based API's there is no need for this field anymore.