Allowing concurrent persists | laravel-event-sourcing | Spatie SPATIE Laravel Event Sourcing ========================= spatie.be/open-source [Docs](https://spatie.be/docs) [Laravel-event-sourcing](https://spatie.be/docs/laravel-event-sourcing/v3) Advanced-usage Allowing concurrent persists Version v7 v6 v5 v4 v3 v2 v1 Other versions for crawler [v7](https://spatie.be/docs/laravel-event-sourcing/v7) [v6](https://spatie.be/docs/laravel-event-sourcing/v6) [v5](https://spatie.be/docs/laravel-event-sourcing/v5) [v4](https://spatie.be/docs/laravel-event-sourcing/v4) [v3](https://spatie.be/docs/laravel-event-sourcing/v3) [v2](https://spatie.be/docs/laravel-event-sourcing/v2) [v1](https://spatie.be/docs/laravel-event-sourcing/v1) - [ Introduction ](https://spatie.be/docs/laravel-event-sourcing/v3/introduction) - [ Support us ](https://spatie.be/docs/laravel-event-sourcing/v3/support-us) - [ Requirements ](https://spatie.be/docs/laravel-event-sourcing/v3/requirements) - [ Installation & setup ](https://spatie.be/docs/laravel-event-sourcing/v3/installation-setup) - [ Questions and issues ](https://spatie.be/docs/laravel-event-sourcing/v3/questions-issues) - [ Changelog ](https://spatie.be/docs/laravel-event-sourcing/v3/changelog) - [ Upgrading ](https://spatie.be/docs/laravel-event-sourcing/v3/upgrading) - [ Resources and alternatives ](https://spatie.be/docs/laravel-event-sourcing/v3/resources-and-alternatives) - [ About us ](https://spatie.be/docs/laravel-event-sourcing/v3/about-us) Getting familiar with event sourcing ------------------------------------ - [ Introduction ](https://spatie.be/docs/laravel-event-sourcing/v3/getting-familiar-with-event-sourcing/introduction) - [ The traditional application ](https://spatie.be/docs/laravel-event-sourcing/v3/getting-familiar-with-event-sourcing/the-traditional-application) - [ Using projectors to transform events ](https://spatie.be/docs/laravel-event-sourcing/v3/getting-familiar-with-event-sourcing/using-projectors-to-transform-events) - [ Using aggregates to make decisions based on the past ](https://spatie.be/docs/laravel-event-sourcing/v3/getting-familiar-with-event-sourcing/using-aggregates-to-make-decisions-based-on-the-past) Using projectors ---------------- - [ Writing your first projector ](https://spatie.be/docs/laravel-event-sourcing/v3/using-projectors/writing-your-first-projector) - [ Creating and registering projectors ](https://spatie.be/docs/laravel-event-sourcing/v3/using-projectors/creating-and-configuring-projectors) - [ Making sure events get handled in the right order ](https://spatie.be/docs/laravel-event-sourcing/v3/using-projectors/making-sure-events-get-handled-in-the-right-order) - [ Thinking in events ](https://spatie.be/docs/laravel-event-sourcing/v3/using-projectors/thinking-in-events) Using reactors -------------- - [ Writing your first reactor ](https://spatie.be/docs/laravel-event-sourcing/v3/using-reactors/writing-your-first-reactor) - [ Creating and configuring reactors ](https://spatie.be/docs/laravel-event-sourcing/v3/using-reactors/creating-and-configuring-reactors) Using aggregates ---------------- - [ Writing your first aggregate ](https://spatie.be/docs/laravel-event-sourcing/v3/using-aggregates/writing-your-first-aggregate) - [ Creating and configuring aggregates ](https://spatie.be/docs/laravel-event-sourcing/v3/using-aggregates/creating-and-configuring-aggregates) - [ Testing aggregates ](https://spatie.be/docs/laravel-event-sourcing/v3/using-aggregates/testing-aggregates) - [ Snapshots ](https://spatie.be/docs/laravel-event-sourcing/v3/using-aggregates/snapshots) Advanced usage -------------- - [ Preparing events ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/preparing-events) - [ Replaying events ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/replaying-events) - [ Storing metadata ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/storing-metadata) - [ Handling exceptions ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/handling-exceptions) - [ Discovering projectors and reactors ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/discovering-projectors-and-reactors) - [ Using your own event storage model ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/using-your-own-event-storage-model) - [ Using your own event storage repository ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/using-your-own-event-storage-repository) - [ Using your own event serializer ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/using-your-own-event-serializer) - [ Using aliases for stored event classes ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/using-aliases-for-stored-event-classes) - [ Adding and Removing Projectors and Reactors ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/adding-and-removing-projectors-and-reactors) - [ Allowing concurrent persists ](https://spatie.be/docs/laravel-event-sourcing/v3/advanced-usage/allowing-concurrent-persists) You are viewing the documentation for **an older version** of this package. You can check the version you are using with the following command: ` composer show spatie/laravel-event-sourcing ` Allowing concurrent persists ============================ Whenever an aggregate is persisted, its versions will increment for each event that was saved. When reconstituting an aggregate from previous events the aggregate will remember the highest version id for that aggregate. If that highest version id differs from the highest one that the aggregate remembers, an exception will be thrown. This can happen when there are two concurrent requests that try to update the same aggregate. If you want to disable this check, and thus allow concurrent persists, you can set the `$allowConcurrency` static property on the aggregate. ``` use Spatie\EventSourcing\AggregateRoots\AggregateRoot; class AggregateRootThatAllowsConcurrency extends AggregateRoot { protected static bool $allowConcurrency = true; } ```