New projection starting from checkpoint and not from start #156
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services.AddSubscription<AllStreamSubscription, AllStreamSubscriptionOptions>( When I added ThirdProjection / event handler , It start listening to new event maybe because of the checkpoint store ? Can you suggest something here ? |
Replies: 2 comments · 3 replies
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This is urgent and concerning issue |
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Subscriptions start from the checkpoint stored in the checkpoint store by subscription id. Adding a new event handler does not force the subscription to replay all the events for that particular handler; it will continue from the last know checkpoints. It's all described in the docs. If you add a new handler that needs to start from scratch, you either need to replay everything by deleting the subscription checkpoint or create a new subscription for that handler alone. |
(when it's reached the tail, you can then collapse the handler into the other one, if that still makes sense) |
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Yeah, that was implicit from my side :) I can think of something to make it work, as it could be useful, but I am not sure when. It would require changing the checkpointing quite substantially as every handler would need to have its own checkpoint. |
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Yes definitely wasn't expanding that for you, Alexey! |
Subscriptions start from the checkpoint stored in the checkpoint store by subscription id. Adding a new event handler does not force the subscription to replay all the events for that particular handler; it will continue from the last know checkpoints. It's all described in the docs.
If you add a new handler that needs to start from scratch, you either need to replay everything by deleting the subscription checkpoint or create a new subscription for that handler alone.