Replay events about laravel-event-sourcing HOT 2 CLOSED

How we should properly reset state in replaying event from X event number?

This is critical.

Off the top of my head, I am wondering how to build around this. Since there are not really hard rules set in stone about projectors being actually linked to specific tables etc.

Otherwise, it seems like the event or projection itself would need metadata linking it to a specific event number, so that something automated could theoretically only delete all projection table entries that are sourced from event >= 5.

Maybe a trait like projectionHasEventSource which adds like... an identifier column linking it to the event creation. It would also require projectors only ever projecting to a single table, I think. Which is not enforced, and requires following this standard.

I'm not sure a graceful way to build this into the package.

A workaround as you already alluded to yourself, might be to just always rely on replaying all events and never replaying a subset. Although it is far more work if you have a table with millions of rows, in theory the eventual consistency final state should be the same in both. So although it is inefficient, it should work to replay all events if you wipe the entire table and ALWAYS have a 1 to 1 link between a projection and a projector. (Maybe snapshotting will be enough for this workaround to function longterm at scale...)

from laravel-event-sourcing.

Quote from the docs:

If your projector has a resetState method it will get called before replaying events. You can use that method to reset the state of your projector.

If you want to replay events starting from a certain event you can use the --from option when executing event-sourcing:replay. If you use this option the resetState on projectors will not get called. This package does not track which events have already been processed by which projectors. Be sure not to replay events to projectors that already have handled them.

So it would seem the onus is on us when using --from to be very careful.

from laravel-event-sourcing.