How to subscribe to specific events changes

EventStoreDB
1

Hi everyone,

I’m wondering what’s the best way to subscribe to event changes with EventStore.

I mean, when a specific event appears on a stream, I need to start a saga.

Exemple : a new contact has been added. I need to start a saga to apply business processes.

I’ve used _connection.SubscribeToStreamAsync("$et- but I’m not sure if it’s reliable

Any advice?

Thanks for your help.

Patrice

2

That’s been reliable for me. Just store last event seen and reconnect on fail.

Why do you think it isn’t?

3

Thanks for your quick response!

When you say :

Just store last event seen and reconnect on fail.

You mean that’s the default behavior or should I follow this pattern ?

Why do you think it isn’t?

I’m just looking for the best approach and I’m a rookie with EventStore…so that’s why ^^

4

When you subscribe you specify starting event number. If you store this and just reconnect on fail using that number you start from last position.

5

Well, I use SubscribeToStreamAsync method from the .NET Event Store client library.
I cannot specify a starting event number. “Asynchronously subscribes to a single event stream. New events written to the stream while the subscription is active will be pushed to the client.”

6

Given that you are discussing sagas here (guessing it might actually be a process manager as the wording is often loose between the two) you likely should consider utilizing a persistent subscription as opposed to a catchupsubscription. This will allow for having multiple handlers/fault tolerance/etc.

7

Perfect.

Thanks you for taking the time to answer my question, both of you.