Subscription - out of order / duplicate events possible?

EventStoreDB
1

I could not find any documentation whether a subscriber must be able to process out-of-order or duplicate events.

Does the Event Store guarantee in-order & exactly-once delivery for subscribers?

Best regards,

Dominik

PS: Yeah, I’m currently posting a lot, hope you don’t mind, I’m currently doing an in-depth evaluation of your product for our business use cases.

2

It assures in order atleast once. You can make this exactly-once by saving your checkpoint atomically with whatever read model you may be using